Snap packages not installing

so i use kernel 4.19 because my broadcom modem card performs rock solid. but suddenly after an update snap packages wont install …something at the post transaction hook stage. after researching it seems to be an apparmor issue on older kernels. can this be patched.???. I have in the interim installed kernel 5.10 and snap works but am getting connection issues with my broadcom card connecting to the internet. I used to use kernel 5.4 until an automatic kernel upgrade wrecked its ability to connect by remarking the 54broadcom bcmwl out of contention. saying it conflicted when in fact it was the same file as 59broadcom file. took me ages to fix it. even now kernels later than 4.19 have trouble with the broadcom card. at the moment i use a kernel boot with 5.10 to install snap packages and a 4.19 boot for connection stability. surely this could be fixed?