I have had similar problems with USB OTG. It seems to be another thing that just doesn't quite work as it should on the Nokia 8.
I've found some brands of USB drive work and some don't. My Sandisk USB drives are recognised by the Nokia 8 when connected. My Patriot USB drives aren't recognised when connected. Any other brand is as good as random from my point of view. I don't know why it happens like that.
Thanks for commenting to my query.
Another peculiar behavior. After i tried various Pendrives ( none allowed MTP or any type of file transfers, yet in notification it shows the message - "Power supply- Charge the other connected device"), there seem to crop up a charging issue. The phone wont charge simply by connecting to the Type C charger it came alongwith. I had to restart the device and then it started to charge!!!???!!!
anyone else with such prob?