I have crafted the first toolbelt and the other 3 are not unlocking. Having read that there is a known glitch i went back and managed to create the 1st toolbelt a second time which unlocked the second slot. I am host on multiplayer. I know am unable to make anymore of the 1st toolbelt and the 2nd, 3rd and 4th belts are locked and greyed out. The first is locked and even with the correct crafting materials will not lete craft it. Im playing on xbox series x. And have the latest update/patch. Please help.
Hi Charleeze, how much ingame time did you let pass after making a tool belt? I found that if i let a couple days go by I could then make another belt. Also noticed the components never changed, so it was like I made 4 of the #1 belts. And a couple ingame days after unlocking my 4th slot, it let me make a 5th belt BUT it did not give me a 5th slot! as i’m on a console and only PCs get more than 4… 
Im host in my game too, and my player2 was able to repeat what I did to unlock all 4 slots as well.
Hi Charleeze, welcome to the forums,
Thank you for reporting this issue and I’m sorry to hear it has affected your save.
The issue with tool belts not unlocking is one the team are aware of and have created a fix for, it is my understanding that they’re currently testing this fix.
I unfortunately do not have a timeline for when the fix will be released but there is a workaround that can allow players to craft the next slots in their toolbelt. This workaround is what @Picaro was describing below (Thank you Picaro!).
While Picaro allowed some in-game time to pass, I believe it should also be possible for you to craft a toolbelt, save and quit, reload the save and there should be an option to craft the first toolbelt again. This should in turn unlock each of the toolbelts the way Picaro described.