48khz not supported

[Dale-c]

I am running 2018.7 in El Capitan.
I use two different Interfaces, one is a Profire 610 and the other is a mobile pre. Both M-audio brand. Both had driver support abruptly end at Yosemite but the 610 works fine in El Cap. The Mobile pre however doesn't but since it is USB, I can just use it with class drivers. I have used this for years with class drivers in Pro Tools first but now after updating to El Cap I can't load the drivers and running without drivers says that 48k isn't supported. SO when I open a 48k session, the playback in slow.

For any serious recording I would use the ProFire anyway but the reason I have both is that I normally have my iMac booted into Catalina for day to day work and my mobile pre is connected to my studio monitors. I don't want to reconnect everything needlessly.

Is there anyway to make this work on 48k? The interface supports 24/48 so it should work.