Support was actually not helpful. I got a message from the developer after purchasing a license, asking how things were going. I explained the problem, and here was his reply:
Google indeed updated their mobile bot's user agent a couple months back, so the old version of the device database doesn't recognize it as a mobile device. We only support officially our 2.x version nowadays, so the device database update where the new Google mobile bot is included is only available for it.
It's possible to get the update also to old 1.x versions, though but does require a bit of workaround: the simplest way is to install MJ 2.x on a test website, export #__mj_amdd database table, and import it to MJ 1.x website. It will likely be necessary to truncate #__mj_amdd_cache table as well to use the new data immediately.
I tried it and it worked!
Support, please note this workaround. Thanks