Thanks for your reply Alex.
I have uninstalled all LG drivers using the uninstall function of their apps from the .dmg's I downloaded from the LG site. I have uninstalled Android File Transfer.
I don't know what you mean by "the link to this file was sent to you by email", because there was no link in the email you sent me. But anyway, there is nothing from LG on my Mac.
I have activated USB debugging and MTP in USB options when I connect my LG G5 (Android 7.0) to my Mac.
There is no screen shot to send of the popup window because there is no popup window. Commander One does not recognise my phone, or phones. Because I also tried with an LG G3 (Android 5.0). Not recognised, no reaction from Commander One.
The problem doesn't seem to be my phones or my USB cables. When I connect the phones and select PTP to send images, the Photos app opens automatically and gives me all the options to transfer, upload, etc.