I've read some posts from the past related to freezing file operations when DOpus is using MTP to manage files and folders on e.g. cameras and Android phones. But I still don't know if those issues are going to be fixed anytime soon or if it's a general problem in DOpus.
In my experience copying files from a MTP device to your PC works just fine. But as soon as you start to manage files on the devices (especially moving and deleting content) DOpus freezes during those operations and the operation's dialog never disappears again until you disconnect your device.
So if I have to manage files on those devices (especially on Android) I have to start the original Explorer. I don't like to use it but in case of MTP it is rock solid and nearly never freezes. So the question is why can Micrsoft handle MTP so well while DOpus can't do it?
Basically, it's because MTP is a poorly-designed, single-threaded protocol where both the Windows and Android implementations have some serious bugs (although newer versions of Android tend to be better... but a lot of Android phones don't get OS updates).
The issues affect Explorer as well, albeit less so, probably because the Windows MTP stack was written and tested for Explorer and nothing else.
You can try toggling Preferences / Miscellaneous / Advanced: mtp_enable in Opus which sometimes gives better results.
When set to False, it makes Opus delegate MTP folders to the Windows shell, essentially embedding an Explorer window inside the Opus window.
When set to True (the default), Opus handles more of the details itself, and has full control over the file display (but still ultimately depends on the Windows MTP stack to communicate with the phone, and the phone's MTP stack to communicate back).
Alternatively, use FTP/SFTP, which are reliable protocols with good Android servers, and have the bonus of not requiring a USB cable or involving the Windows or Android MTP stacks at all.
FYI, I've noticed that on the current Beta of Directory Opus (12.0.5) I'm unable to get an MTP connection to android devices when MTP_ENABLE = true, but if I set MTP_ENABLE = false, MTP is working OK for me.