My tethered session between Capture One (V20 Build 13.1.1) failed yesterday when the software could not connect to my Fujifilm X-T3. As a result I had to abandon tethered shooting and rely on the camera's rear view screen instead. Normally this is rock solid and far more robust than tethering to Lightroom, as I used to.
Today after a bit of investigation I've identified that it was the active Bluetooth connection between my Android phone and the X-T3 that appeared to be holding down the connection.
So, if you find that all of a sudden your Capture One Fuji camera session breaks navigate to
Spanner->Connection Setting->Bluetooth SETTINGS
and turn off Bluetooth there. A side effect of this appears to be that the camera loses the Geo-location data from the phone.
I've not yet found any mention of this issue or a work around on the web, but I'll keep investigating.