Help using Tags

I have a mod with some accesory items that you can equip and get various buffs from them. I'm doing an accesory that works with a trident in the main hand, but i wanted this to work with other modded tridents too, so i created a tag named forge:weapons/trident and added some tridents to it, i then went to the procedure section and created a block to check if the player has an item tagged as forge:weapons/trident in its main hand, but it doesn't work for some reason. I'm maybe doing something wrong? I used a block to compare (if item in main hand is tagged as [tag] = true, then do the thing).
Thanks if you could help me