hello, as @arinc9 mentioned, you can either build with the packages you want or follow this solution (which I did): Users needed to test Wi-Fi stability on Linksys WRT3200ACM & WRT32X on OpenWrt 21.02 - #530 by cotequeiroz
You can install a stock 21.02.1 image from the main site, ssh in, force uninstall the (4) modules shown in the drive link [opkg remove --force-depends kmod-mwlwifi and the same for the other (3) modules], and upload/install the modified packages from @cotequeiroz's Drive in LuCI [System -> Software -> Upload Package].. fixes the connection drops and I was able to install sqm without issue.
I would also recommend restricting ssh access to the LAN, since that is not the default setting, for security purposes unless you use it from elsewhere and are familiar with a secure ssh setup.