PTP 820 6 GHz random reboot

Has anyone had any issues with a PTP820 rebooting after a year or more of run time? I’ve got multiple PTP820’s and after running a year or so they seem to randomly reboot and then it will be fine for another 12 months or so.

Units are feed from a dual-redundant UPS system, no other devices have lost power or had issues. The event log shows nothing other than indicating it came up from a cold boot like it had been power cycled.

Currently running on 10.5.0.0.0.258 but I’m wondering if maybe there is a memory leak or something in the unit. Specific model # is C060082B014A

Thanks!