I’ve searched the posts and I can’t seem to find a solution. I am trying to create a magic item that will increase the character’s strength and reduce the character’s intelligence. I’ve got the strength with no problem, but I can’t get it to reduce the intelligence. I added two modifiers, set strength to 19 and that works fine. The other is set intelligence to 5 but it will not actually make the change on the character sheet when the character puts the item on. The strength will change, but intelligence will not. How can I fix this?

Yeah, the set modifier won't set to a lower number (all the items with this modifier are intended to be raising stats).

You could try a bonus with a negative value (can't set this way though).

I'm quite late to this one here, but I figured I'd reply with a hacky solution I found. It is possible to achieve the reduced (or increased if intellegence was already lower) stat by using two modifiers, instead of one.

In this case the first on would be: Set: Intellegence Score, 5

since the Set modifier always has priority we can then simply remove a large amount from the base intellegence score: Bonus: Intellegence Score, -15

This worked for me