If you set Preferences / Miscellaneous / Advanced: mtp_enable = False, Opus should fall back on using the Windows shell (Explorer, essentially, but inside the Opus window) for MTP devices, which may be a workaround.
We have only tested MTP support with Android phones, which are the main focus of it. Other devices (and some Android phones, for that matter) seem to have quirks in their MTP handling which can trip-up Opus (and sometimes Explorer, too, but obviously most device makers test things with Explorer so it's less likely).