Sounds very familiar, sadly.
Was working fine listening to a station until the forced upgrade prompt came up. After upgrading the radio would not connect to the router sitting on 'verifying key' for a prolonged period. Thought the wifi key had been erased, replaced it to no improvement. Then factory reset and installed the update via USB, same.
Even when it does find the router i've seen it go from 4 bars to dropping the connection completely and can take anything up to 30 minutes to reconnect.
Been quite cheesed off for a long while at having these updates forced as all they have done is made the radio more and more unstable. Typical of Pure to dump a bug infested update and then be in denial about the pile of crock inflicted on users. Cannot suggest anything, only Pure can fix this and in their eyes they can do no wrong.
I'm done with Pure products and will be going Raspberry Pi or Android next time.