R7960P firmware not upgrading

Mrfatboy Thank you very much for the link.  (Fighting illness makes it difficult to do basic things like searching).  I haven't tried it yet because of the work involved in re-linking all the varying smart devices we have, even after naming the network the same and the family needs it working for a few days for work.  (Sorry, slightly off topic for a bit but there is a reason I mention that after restoring to a config file from a month ago, before the 50 firmware when there were fewer problems - the biggest problem I have is the router handing out duplicate IP's and misreporting a number of connected devices, even after turning all 24 off in the house and adding them back one by one.  Reserving IP's for some #'s that were always duplicating didn't help.  Duplicate IP's are causing connectivity problems and complete failures.  The reason I mention this is normally I'd be happy to factory reset if I new I could restore to a working good config...but I'm concerned that the config is corrupt and I will have to start from scratch - requriing hours of configuration thanks to our cheap (as needed unfortunately) but many different devices we have for house automation. 

What I'd really like to find out is if someone who can't upgrade from 50 to 62 w/ the same symptoms I'm having trying to upgrade - is successful after a full reset (same question as posed by @Mrfatboy).  Not asking anyone who was successful to mess with a downgrade of course!...but if anyone w/ a little more time and inclination and health could try this before returning their router, I'd be very grateful!   

I am concerned Costco at some point may stop taking this one back - which I got in Dec or Jan. so I like the idea of exchanging for the AX8 - possible a temporary one if it has problems until the Asus' become more available and hopefully discounted.  I'll have to look and see if it will serve us ok in the meantime.