Tried Firmware 4.4.5.5 this morning on a brand new 2927ax we were configuring.
Router reboots every 15 minutes, rolled back to 4.4.3.1 and all is stable.
All of this is leaving us very wary of newer firmware, we have had this issue on many 2927 routers at this stage.

 

I've a 2927AX with 4.4.5.5 and it's been very stable.

I've not had a reboot that I didn't instigate since I've owned it, so about 6 months.

I have, however, upgraded each incremental step as it's offered new firmware.

I've suffered the scrambling of the LAN IP address reservations (Bind IP to MAC) and currently the QoS page has gone AWOL but stability hasn't been an issue.

It's worth trying upgrading in smaller steps.

Is it perfect, absolutely not but it largely does.