Can confirm I am having this issue as well. It occurs most often at my base, which is a minimally upgraded village with less than 50 villagers.
it does not, however, occur there exclusively. This was happening frequently as myself and the two other players were spread throughout the world in an undeveloped the ancient city and the nether. In these situations, it manifests mostly in jittery minecart rides, where the minecart stops frequently (presumably when loading chunks) and delayed or undone block breaks (a couple blocks will be broken, no debris will fall, no sound will occur, and moments later, the sounds will occur in rapid succession and the blocks will reappear and break instantly. In placing blocks, this often results in the blocks placed returning to inventory. Behavior is much like a momentary timeout/lagswitch.
Those of you with larger bases appear to be experiencing this on a level exponentially worse than I, but it still occurs painfully often in mine, which is:
Less than 1,000 square blocks
Fewer than 50 villagers
Not more than 30 double chests
a small redstone subway
A handful of item frames
It became so bad today, however, that I tried something else when my teammates began really suffering.
1) saved the world locally (PC)
2) renamed it to a short name (also dealing with the long name bug right now)
3) Reset the world in my first Realms slot
4) Uploaded the save
Timeouts still occur (delayed chests, delayed block breakage/blocks reappearing after breaking) but it has become a bit less frequent.
I added a clip to the pool of a pufferfish freezing in midair and my rod becoming unresponsive.