I have created a homebrew item that regains all its charges on a long rest. However when my player equips the item, it tells him the charge condition is other, and long resting doesn't recharge the item.

Charges on magic items do not automatically recharge. This is because most will have the stipulation of gaining 1d# of charges back upon meeting the recharge criteria. Whatever the case, the player simply has to click the charges used to refresh them.

That's fine, but why does it say "other" instead of "long rest" like it's set to?

Did you set it to Long Rest and not Other?

I did indeed set it to long rest and not other. I double checked and removed/re-added the item to their sheet to be sure.

Try re-saving the entire magic item.

Also, keep in mind that there are no official Magic items with charges that refresh on any rests. Any item with charges refresh at dawn (or midnight, etc.), and anything that refreshes on a rest (like Rod of the Pact Keeper) isn’t actually a “charge” at all, they just got programmed that way because they haven’t added actions to Magic items yet.

Thanks for the help

Did re-saving work?

Unfortunately not. It's fine, I'll remember if my player doesn't

The Mods will want to look into it. Please post a link to that Homebrew so they can. (They can even look into unpublished homebrews.)

Good idea, I'll leave the unpublished link here in case they want to have a look at it

https://www.dndbeyond.com/magic-items/2853110-warped-bloodcasters-ring

EDIT: I have changed the recharge rate to 1d10 daily at dawn to better fit with existing standards, rendering my issue null and void