I’m also seeing random disconnects. But in my case it is an i-tec dock. Nevertheless, this issue might be related with what you experience with your 1TB extension modules. I would like to find out, whether this is the case.
I noticed that the disconnects of the dock only happen, when the chargelimit of the battery has been reached. So I’m wondering, whether your disconnects are also limited to the battery having reached the maximum charge level.
Using ectool from GitHub - DHowett/framework-ec: Embedded Controller firmware for the Framework Laptop the command
ectool battery
shows three digit charge rates shortly after disconnects. I think this is rather high considering that the battery should not charge. Therefore, I experimented with
ectool chargecurrentlimit 0
which is supposed to keep the charge rate at zero. This actually helped and I’ve never had any disconnects any more after invoking this command.