Wireguard dkms module fails

Wireguard for VPN is installed and works on my Openwrt router and 2 iPhones. Only my laptop is a problem. It is an old (2010) MacBook_Pro converted to linux only usage. I have a few distros running on it--recent but not the latest versions. This machine fails to suspend/resume with the most recent Ubuntu LTS, but will work for a slightly older version like Xubuntu_18x LTS. Wireguard is not in the 18x repo but is available thru PPA. However, when I download that version along with wireguard-dkms and wireguard-tools (which all seem to downloaded correctly) the kernel module fails to build. I've tried many things trying to get the latest LTS to suspend/resume but it seems like a dead end. If someone has actually done this (not kinda, sorta), please post how you did it.

Otherwise, I think the most realistic options are compiling from source either wireguard and/or the linux-kernel. I'm a fairly experienced linux user, but a newbie at compiling stuff. Suggestions greatly appreciated!