Had a horse tied to a fence post with a lead. Got on the horse to ride it and saw the lead appeared broken ... not attached to the fence post and visible on the ground (the lead as a tether/leash, not as an item icon). Rode a chunk or two distance away. Went to attach a lead to the horse to tie him up in this new location and the lead will not attach. Only command option is to ride the horse. 

I tried each of the following steps to resolve, none of which have worked:

1. returned with the horse to the original fence post
2. destroyed original fence post
3. saved and quit game, reentered
4. saved and quit game, restarted Minecraft
5. rebooted Xbox

Google searches have turned up a couple of references to this type of error, but from years ago.

• MC-14826 Leads in unloaded chunks break, become invisible or connect to an invisible target far away - Jira (mojang.com) (2019; note: Java edition)
• (2) Invisible lead stuck to horse : Minecraft (reddit.com) (2019)

Those are the only two references I can find. This error just happened for the first time.