Ok, so a not great solution but one that works is to open up “mobile-detect.php”, go to line 187 and remove “GOA”. The downside is, of course, GOA phones may not be detected as mobile anymore (I don’t have one to test with).
So, ultimately, you’ve got to decide whether it’s more important for an obscure Linux browser to not be detected as mobile, or to be sure an obscure French phone will be detected as mobile.