• Which ReplayMod version are you using?
  replaymod-1.15.2-2.3.0.jar

preview_OptiFine_1.15.2_HD_U_G1_pre16.jar
optifabric-1.0.0-beta8.jar
fabric-api-0.5.1+build.294-1.15.jar
malilib-fabric-1.15.2-0.10.0-dev.20+arne.6.jar
litematica-fabric-1.15.2-0.0.0-dev.20200309.150609.jar
fabricmod_VoxelMap-1.9.16_for_1.15.2.jar
fabric-installer-0.5.2.39.jar
minihud-fabric-1.15.2-0.19.0-dev.20200121.203515.jar

• What did you do?
  Playing normally on a server.

• What did you expect to happen?
  I expected to see 27 chunks being loaded as per setting in my Minecraft Setting. This was never an issue while using any version of OptiFine.

• What did actually happen? (the bug)
  I get the default server rendering distance of 10 chunks. With Chunks out of server render distance to unload.

• The debug.log, or, if that doesn't exist, the latest.log (taken directly after the bug occurred). These logs are located in .minecraft/logs.
  2020-05-10-4.log.gz

This is pretty much it. This only happens when I start minecraft with ReplayMod.
I cannot recall seeing this behaviour in previous versions of Minecraft and ReplayMod combinations. Last time I used ReplayMod was 1.14.4 and because I was working in a closed environment it wasn't an issue.

1.14.4 replayMod recording: https://youtu.be/6Spciv8kM5c?t=11m16s

1.15.2 ReplayMod impact on live gameplay: https://www.twitch.tv/videos/616857284
Between 0h30m and 0h40m of the video you can clearly see the night and day difference of preReplayMod gameplay and with ReplayMod gameplay.

*Edit: On 0h42m is the best example of what is happening.