Some Samsung devices will drop their adb connections even after the initial “unstable” period after connecting. Disconnecting and reconnecting the device has not shown any progress. Disabling and then re-enabling the device’s and host’s ADB servers has not been fruitful. At this point, I would normally double-check what the USB storage connection type the device is set to (e.g. some devices will only allow ADB access when their storage mode is set to one of PTP or MTP), however my problematic Samsung device has no option to toggle the storage type. Rebooting the device is not helpful either.