I've had far more luck taking a standard powered 2.0 hub and using one of these micro adapters: https://smile.amazon.com/gp/product/B015GZOHKW
Works so far on everything I've tried or can direct connect a wired/wireless keyboard for setting up BT. Plus cheap as dirt for a pack of them. Paired with a sub $20 10 port hub I've never had a problem since. Real OTG devices tend to be spotty at best.
the dongle is a usb wifi adapter with a tiny little usb a to microusb adapter, so I can use wifi if/when I need it since the cm3 doesn’t have wireless.
EASTECH Ralink RT5370 Raspberry... https://www.amazon.com/dp/B019XUDHFC?ref=ppx_pop_mob_ap_share
and
CHENYANG Ultra Mini DM Micro USB... https://www.amazon.com/dp/B015GZOHKW?ref=ppx_pop_mob_ap_share