Lagging out of server when going through a Nether Portal.

Hey all.

I've been lagging out of my server when I've been trying to go through Nether Portals.
This appears to be happening when I'm trying to load into places which are quite built up. Nothing too crazy, just a few shops in a market area. It is also happening when I try to load through a portal to my own base, which is nothing special, just a house, a couple of manual farms and a basic mob farm. I have experienced the disconnect from server going from the overworld to the nether, yet no where near as frequently.

Using a pretty beastly PC that can run new top of the line games, so fairly confident that isn't the issue. Also my internet connection is very stable.

I'm seeing complaints of this issue going all the way back to 1.9 days on a Google search. Thought I'd bring it here to see if anyone else is experiencing this / we can find some commonalities between users having this problem.

What is particuarly strange about this occurance is that it appears to only affect a handful of players. There are players on my server with a lot worse internet connections than my own, who seem to be unaffected by this. I even read one thread about a husband and wife using identical setups, where the wife had the disconnect issue, yet the husband did not.

I appreciate the usual responce might be "try decreasing chunk distance" or "install optifine", but it seems to make more sense to me that we try to fix this.

Note that the server console presents no errors, only logging my "disconnect".