I don't see that CSCvi09153 is fixed in any upcoming build of 8.3 or 8.5. We have.a flex deployment of about 5,000 APs running 8.3 MR4 where we're seeing this and current workaround is to just reset radios every morning.
If we could get this added to the list for an upcoming MR of 8.3 or 8.5 (preferably both) this would be great.
I already have a TAC case open on this since 3/19/2018 and I have been waiting on a fix since then.
Thanks.