Also make sure that your device can access OTG correctly. IME, having done lots of volunteer customer troubleshooting for a device manufacturer & depending on what version of Android that you have, the default Android File Manager very often did not connect well to OTG devices, leading one to believe that it was the device, the cable or the other device that was at fault, when really it was the Android OS File Manager that was at fault, as it can be extremely basic & not at all user friendly.
Install a 3rd party File Manager that has built in OTG capability, some are free, some are paid. I use Total Commander with a plug in sold by TC & I also use Mix File Manager successfully. There are others. Do some searching regarding use of on OTG. There, are some how to articles on makeuseof.com or howtogeek.com as well as other sites, & or YouTube videos. But first, I'd use the cables that you've got & install an OTG capable File Manager from the Google Play Store & or read or what some How To's, just to be 100% positive that it's the cable that is at fault. I realize that you are using the Mobius app but still, try installing a 3rd party file manager. You also don't mention the device brand or Android OS version, which you should. Some Mfgs highly customize "Android", such as Samsung & Sony, so it ends up not really being a true Android OS, which adds troubleshooting complexity for OTG. Then again, it could be the cable, I've not found that to yet be the case.