I added permissions /lp group default permission set worldedit.calc false
But players can still use the //calc command
LuckPerms-Bukkit-Legacy-3.2.58

Use the verbose command to debug it. It's most likely not a bug in LP

The problem was solved by updating to WorldEdit 6.1.7
In the old version there was no check for these commands and they crashed the server.
//calc for(a=0;a<100000;a++){for(b=0;b<256;b++){for(c=0;c<256;c++){for(d=0;d<256;d++){ln(pi)}}}}