Not quite sure what you´re talking about.
Normally the whole game including all sideloader modpacks are downloaded as BetterRepack.
Belonging to troubles with splitted packs look here
https://f95zone.to/threads/honey-select-2-dx-r13-illusion.53457/post-11662617
If you download single sideloader mods from here they are already .zipmod files - DON´T extract them, they have to directly copied into mods/Sideloader-Modpack xxxxx.
Mods form other sites you find and download yourself going to mods/MyMods ( if they are .zipmod fi
Sry have to say, but I´m nearly daily in these HS2 threads and I can´t confirm your presumption - this isn´t a common issue of this game.
I myself never had troubles with the cursor ingame.
Anyway it cannot be excluded that certain mods causing issues, but rather extra mods and not from sideloader.
If you have your personal downloaded mods in mods/MyMods as recommended, you can try to store your MyMods folder outside the game and run it only with the sideloader mods.
Also update your sideloaders can help.