When trying to create a deck in the underground arena no hero comes up, if you go back, as it’s one of the only options available, if you try to go back into it it gives you the edit deck option. Now here is has the starter cards and the few starter cards, however when you try to add cards it states limit cap exceeded and error comes up as asks you to revert cards. However when you try to do so an error occurs and it doesn’t allow this to happen. You are locked in this screen and only option is to quit. However if you restart and try to redo this those cards appear to be locked and it is counting the hero as an actual card. The only way to break this appears to be to retire. But this means you’re forfeiting your arena tickets as I’ve already lost 4-6 tickets doing this, as it seems to be a repeatable bug. This does let you return to normal operations for one play through attempt, but then happens when you try to start a new underground arena cycle. Never appeared to have this issue in the normal arena.
Now I have run an integrity check and update check as system is not reporting any issues.