Is packet loss present when connected using ethernet (wired)?
The downstream/upstream data does not exhibit problems. The log does not contain events after June 27. Could you post the OFDM channel data, displayed under '3.1 Downstream channels'?
Could you post one or more pictures of the AOP (main outlet in meter cupboard or living room) and cables, plus splitter(s) and signal amplifier, as applicable?
Since you are in a former UPC area (indicated by the six US/ATDMA channels), could you write down the first half of your public/external IPv4 address? This is to determine whether Dual-Stack Lite is active, which may cause problems.
Finally, you may notice improvements after disabling all firewall options except 'Firewall protection' for both IPv4 and IPv6.