@xethos @janvlug The issue I described in that talk has a (downstream) fix that has been deployed in PureOS in early 2023. Unless your system is misconfigured, this can't be the problem you're seeing today.
There's another problem with the modem we're seeing - cellular data connection sometimes gets "stale", with no incoming packets being received on the interface. It's a completely different and unrelated issue that doesn't have a fix yet, just a poor workaround (using old-school PPP for data)