Namely the y, t, left tab, left ctrl, brightness up.
My issue came and went over a couple of years. I have always been able to press Space Bar simultaneously to make them work, but even that has ceased helping. I've cleaned the keys of any grime, and made sure the port/pins were clear of all obstruction and aligned. Also uninstalled touchpad driver and restarted which re-installs it.
I tried all the above, but no luck. I have good malware defenses, and the only Synaptics driver I could find was presumably for the touchpad. Because the issue seemed to have semi-gradually escalated, I think it may be damaged or aged hardware, and maybe not software-related.