Installed the mod to prevent players from xraying.

Got complains from a friend that they are unable to play and loose connection every two minutes.
In the console I could see that they are timing out constantly. After an internet search I came across the info that the paper anti-xray patch, which this mod is based on can mess with keep-alive packets. Which in turn can lead to players timing out.

Is there any way to prevent the issue from happening or fixing it?

Engine mode 2 can cause players with slower connection to time out. You could change engine mode to 1, which doesn't have that problem. I am also currently experimenting with a bypass permission (a2631ca), so you can disable antixray for people you trust. I am also currently testing another idea to improve the compression of engine mode 2 (d3f1db2)

Thanks a lot for your answer and effort.
I was using the TimeOutOut mod before, which also seemed to fix it.

For now I removed it and the old version again and trialing the experimental fix. Will report back here after the offending player was online.

Player hasn't been online yet so no conclusive answer. Otherwise I noticed that the default engine mode 1 for nether does not seem to work. I don't know how it was with the other version as we just activated the nether on our server.

Changing to engine mode 2 seems to work though.