Time Loop

Time loops are localised metaphysical events based on an anchor point that is a split-second snapshot taken in time to which the time of the affected area eventually returns. This affects everything within the area, including data, health, and locations. It is nearly impossible to travel in or out of the area of a time loop, as at the reset point you will be brought back to where you were at the anchor point, unless it is a particuarly small one with a long loop. People that entered halfway through the first loop might find themselves stranded in strange places when it resets, especically if using a mode of transportation other than walking, as the person and mode of transport might end up reset to different places. Even things like data or light waves moving through the area will be reset, creating odd, distorted messages and recordings for those recieving them.

Missed Phenomena

The vast majority of time loops go unnoticed due to a number of factors, making it incredibly hard to gather data and research the phenomena, as protecting it from the effects of the loops is nigh impossible.

Size

Most time loops seem to affect only a small area. Apparently, classical human stories where the phenomena are focused on a single town or area are actually fairly accurate. Due to this, unless it is a large or very popular area, most outsiders will not notice or will be caught the reset when the loop breaks, leaving nobody to remember it happening. There is also the fact that much of physical space is actually entirely empty, and many loops probably start and stop in completely empty areas in space that go entirely unnoticed.
Encrypted Transmission Intercepted. Decode?

According to some members of the BDA, the smallest known loop affected a single grove only 11 feet in diameter, while the largest affected half of a sector.

Period

Time loops seem to usually break after just a few repitions, not repeating long enough for people outside of it to notice unless there's normally a lot of travel and messages going in and out of the area. It tends to get brushed off as a few quiet days, especially if it occurs in more rural areas where such repetitive days are normal, if not quite so exactly reptitive.

Memory

When a time loop breaks, due to it naturally breaking down or the far rarer occurrence of it being broken, most people both directly affected and in the vicinity will only remember the events of the loop that was happening when it broke. Stella Dita described it as being like the ripples when a stone is dropped into water - while time will have been progressing as normal outside of the contained bubble of the loop, it breaking creates an incongruity of two different timelines being in effect. To rectify this, everything is also reset to the moment that the loop was in when it broke. However, this does seem to have a diminishing affect across huge disasters - people more than a few galaxies away might have strange feelings of deja vu for a while until their new timeline catches up with the old one.

Manifestation

There is no real visual cue that past a certain point in space there is a time loop occurring. If far enough away, you might be able to note a slight visual distortion at the moment of reset as light waves are disrupted, but at that point people outside will notice objects suddenly appearing or disappearing and the point is mute.
The most effective and reliable way to spot an ongoing loop is actually radio waves, though audio messages of any kind can be used. It is easier to spot without machinery than light disruption, and programmes can be written to catch the sort of repetitions and anomalies that mark a loop resetting.

Localization

Though time loops are naturally occurring and hard to predict or detect, certain things are thought to be able to cause them. Umashi, revered by the Vanari, are one such - their continued presence in one 'place', as understood by three-dimensional beings such as us, can initiate loops due to their extremely high mass and existence in time.
For some reason, it appears to be far more regular in some areas than others, such as the Beta Sector and Alpha Sector. Some of this can be down to increased ability to remember and thus be aware of it for Beta-zone residents who treat it as a random, unworrying but mildly irritating occurrence, the same way Terrans might treat a sudden downpour. The Vanari's lack of a sense of linear time means they are aware of loops even if they cannot remember past ones much at all, and many JaqHadan have eidetic enough memory to get intense Deja Vu during loops and be able to piece together what's happening.
However, the Alpha zone residents, especially humanity, have multiple stories and legends regarding time loops, even if they were previously considered entirely fiction. This suggests that, despite not really having the capability to remember or record the phenomena, they've probably come in contact with it before. Since eidetic memory is a rare but naturally occurring ability, it is possible that this is how it filtered into the public consciousness.
This is best contrasted against species like the Sanadasin, who thanks to Ratak have been shown to be able to remember loops almost in their entirety both during and after them. Overseers of all species, too, should be able to remember time loops when they encounter them - yet even the fictional idea of them is entirely unknown in many [arts of the universe. Altogether, this suggests that time loops do naturally occur more frequently in the Beta and Alpha sectors.
The cause of this is unknown. It may be the thing that drew the Founders to the Beta Sector, or it may be the root cause behind the Founders going there that is shared with this prevalence. With it being near impossible to gather scientific data on loops, it will probably never be fully understood.

Type

Metaphysical, Astral

“Humanity has plenty of stories about time loops, with morals and meanings, but in reality they’re not like that. There’s not some condition to meet, some person to save or learn to love, some time-critical mission to achieve. It’s just a random, natural occurrence.” - Quoted from report by Ratak about the time loop that occurred on Cerberus Station.