devtrackers.gg
We're investigating issues like this at the moment and will sent this video across to the developers because it definitely sucks to have something like this happen.What I think is happening is that on the server you are slightly behind that player, so on their screen they're not walking into you at all. Unfortunately this movement comes to you slightly later (due to the internet speeds not being instant) and it looks like they're 'pushing' you even though they're not.
What gets tricky is that we can't just 'stop them moving you', because on their screen this would result in them having to teleport back in time due to them finding out you were in their way. This would be a much worse experience for everyone than what we currently have.
What I do want to mention, though, is that just because it works this way now doesn't mean we might not find a solution. It's definitely not fun to have this happen as it makes the game feel inconsistent and unfair. We have people much smarter than me working on it, and every video I get shared helps us narrow the problem down further!