Just FYI, Cyberpower, at least for their consumer line, use problematic yellow glue[1] which becomes brittle over time and can become conductive, causing arcing/fire hazards[2][3]. There was also a prior HN discussion about it[4], with some similar experiences.
It can be removed[5], with some effort, though. Given its use in various electronics it wouldn't surprise me if some other UPSes use it, though have only seen discussions about Cyberpower.