Yi Peng 3 crossed both cables C-Lion 1 and BSC at times matching when they broke

October 2023 there was similar incident where Chinese cargo ship cut Balticonnector cable and EE-S1 cable. Chip named 'Newnew Polar Bear' under Chinese flag and Chinese company Hainan Xin Xin Yang Shipping Co, Ltd. (aka Torgmoll) with CEO named Yelena V. Maksimova, drags anchor in the seabed cutting cables. Chinese investigation claims storm was the reason, but there was no storm, just normal windy autumn weather. The ship just lowered one anchor and dragged it with engines running long time across the seabed until the anchor broke.

These things happen sometimes, ship anchors sometimes damage cables, but not this often and without serious problems in the ship. Russians are attempting plausible deniability.

After the Nordstream pipeline attacked and destroyed, its reasonable to expect shortened lifetimes for undersea cables and sattelites.

I think Nordstream is more of a special case. It was clandestine, but definitely not terrorism. It was an attack on enemy infrastructure in pursuit of an actual, real-life shooting war. One can argue that it was a bad (or good) idea, or that it was/wasn't effetive, or even that its externalities were beneficial in the long term, etc...

But it's not really in the same category as casually cutting internet lines to your peacetime competitors out of pique or whatever.

Nordstream is also special because its destruction was not aligned with Russia interests. It limited Europe capacity to import Russian gaz lifting one of the reason which might have made the EU reluctent to fully support Ukraine (and causing a major economic crisis in Europe as a side effect).

Between this and the coyness of most European countries governments at the time to comment on investigation, it's not too far fetch to think that Ukraine might be involved.