No media player detect OTG videos

[Black Panther0]

Hi, I bought a Motorola One Power 2 weeks ago. Although everything is good about this phone, the only problem I encounter is that OTG videos don't show up in MX Player but all of them do show up in Strorage/Gallery and I can even run them but it's inconvenient to play videos from gallery. Does anyone have a solution to this? I've searched a lot and found none.
P.S. MX Players plays OTG videos in my other smartphone HTC Desire Eye running android Lollipop.
P.S I bought a new sandisk 128 GB USB type-C OTG for this one, also I'm running Android 9 Pie

 

[Rukbat]

Restart the phone with the OTG storage device connected, so that Media Scan can pick them up. (MX Player doesn't have a file manager, it just looks in Media Scan's database. And Media Scan runs when you start or restart the phone.)