This app was mentioned in 2 comments, with an average of 1.00 upvote
I'm sorry I can't answer properly, as I've never had this issue myself, but I'd suggest figuring out if gcode sent by a computer works better than the sd card does. If it doesn't, its an even bigger issue with the board.
Try a different sd card reader on your computer, if you have one. See if it's not corrupting the card by accident. If you have a USB extension cable, those could work too. If your phone is an Android device and you have a USB OTG cable, you can send Gcode with 3Dfox (https://play.google.com/store/apps/details?id=com.fox3d.controller)
Just minor suggestions to sort down the problem. good luck!
>Now, you might be saying "this was a waste of time, there's a bunch of apps on the Play Store for that!". And no, they're all just remote control apps. No server apps. No OTG control capabilities (except one, which wasn't even related to OctoPrint).
You can use 3D-fox (https://play.google.com/store/apps/details?id=com.fox3d.controller) to control your printer via a webserver. You connect the phone with either a bluetooth or OTG.