I dont think this would be the CAT OS, rather more the code release perhapsof the WLC. If you had no issues and now you do and the only thing that has chnaged is the WLC code.
Have you HTTP into the phone and pulled down the logs?
Do you have enough coverage with 20% cell overlap?
Check your AP power. I have seen RRM do some odd things after code upgrades.
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
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