There have been reports of a glitch where jumping on a tilled soil block causes it to become a dirt block, creating a rapid vertical movement. This, however, is different. As I'm sprinting across a tilled field, whether empty or with crops planted, it lags me back to a single position and is almost impossible to remove my character from. I have experienced this phenomena on multiple servers, so it's not a plugin. (It's similar to when you're at the start of hunger games and you're in a fixed position until the game begins, except this is worse)

How to recreate:

Get a tilled field, you don't necessarily need it to be hydrated or have crops

Walk across the field. For me, I don't even need to be sprinting, and I get stuck in one of the first two or three blocks. I usually will get stuck on a single tilled dirt block when it's surrounded by any other sort of block

At some point (Sooner than later) you will lag back and will have a rough time getting out, especially if you're in the middle of the field