Homebrew Item Woes: Adding +1 skill or ability checks bug?

I'm trying to create a weapon that adds:
+1 to each Con, Str, and Dex ability check, or saving throw. BUT every time I do, and equip/attune, it for some reason either adds +8 to all skills as well, or +8 to all skills, and + some other absurd number to saves.

Can't seem to find a way around it.

Quote from wagnarokkr >>

What exact modifier(s) did you use when you set it up?

Well, I tried it again two days later - and now it wants to work properly.

So, nevermind. It magically decided to just start working and I did the exact same things as I did previously.