WOW!  Some of my happiest IT Admin days were when I took those out of service and replaced them with Cloud Key Gen2 Plus devices or a Dream Machine Pro.  The Unifi NVR was end-of-life on January 1, 2021.  I have no idea if that is your issue but at one point I have 5 of them in various locations and I think everyone was replaced or I repaired it.

Its easy for me to spend your money but I'll tell you that the Protect version is light years ahead of the Unifi Video platform and well worth the cost to upgrade.