Yeah, I've never seen a ""Ranging Request Retries exhausted" in my logs during normal operation.
Also, when we had an issue, the engineer that came found the issue and fixed it within about an hour. The fact more than just you in your apartment block has an issue should really narrow it down.
Once you get it fixed (assuming you do before you give up and quit UPC!), work out how many days you've not had a good service, and post back here and ask for a gesture. By that, I mean an official one from UPC not just a "oh dear, you poor thing" from other customers like me