Since 7.6 I have been having issues with multiple quectel RM520N-GL modems keep disappearing and reappearing form interfaces list. It is happening from 3 wAP R ac units. The issue can be resolved by reverting back to 7.5 stable. the log files shows error “mbim: error: wdm send failed: 19” The modem is running firmware RM520NGLAAR01A05M4G
How are you fitting 520Ns on a WAP R AC? There are some board components that block the mpcie to m.2 adapters, never mind the longer ones for 5G modems. You got any pictures?
I use a NGFF M.2 To Mini PCIe Mini PCI-E Adapter For 3G 4G Moudle M.2 to mini pcie
https://www.aliexpress.us/item/3256802187999188.html?spm=a2g0o.order_list.order_list_main.12.21ef1802xyxdGP&gatewayAdapt=glo2usa&_randl_shipto=US
the only problem i have with the adapter is the modem is to long for the screw slot so it is held on with a twits tie.
Here is a picture of it.
https://photos.app.goo.gl/pjY5iRK3dWcoMbmS7
The 7.7rc1 seems to have fixed the issue, has been running fine on 2 of the 5 units i have rm520n-gl cards in
How hot does that get with no heatsink?