You seem to be double posting.
You mentioned much of the same exact problem 6 months ago in
https://forums.ulyssesmod.net/index.php/topic,9638.0.htmlDid you read what MrPresident said and asked?
Did you remove ULX from your server, run the same exact gamemode as before you had the problem, and did it affect the outcome?
Team Ulysses, MrPresident, and I as part of that team are not saying that somewhere in the unexpected folds of the time and space continuum that it isn't possible what you describe to be caused by ULX; we're just experienced enough with ULX antimatter physics that we want proof.
There's no code in ulx that would look for or touch, by themselves, the sv_cheats, ent_fire or its flags straight from console.
If you are trying ulx rcon or "ulx ent" commands, THEN, and only then, there's slightly more complication involved, likely due to the fact Gmod doesn't allow transfer of some commands from lua. You likely wouldn't be able to use ulx ent or ulx rcon for what you're trying.
Prevention of ulx rcon/ent commands from client to server isn't a bug.
It's a Gmod limitation design to enhance security.