Strange lighting anomalies

The YukonXL has been out to pasture last couple years after using it for a cross country trip. I've been going through everything for a couple weeks now to make it road worthy again.The DRLs stopped working some years ago. The right socket burned out years ago and was replaced once. I replaced with new sockets, new 4114LL bulbs. And new correct head lamp bulbs throughout. Also swapped out the high mount tail lamp and replaced pairs of tail lamp bulbs as well. Also replaced the ambient light sensor. Replaced some fuses. Cleaned connections. Etc. Here's whats strange: I can't get the DRLs to come on and the head lamps come on instead. In gear, parking brake off, switch on. Just head lamps. I swapped out relays, no change. Here's the other thing: The 3157 amber indicators now alternate flash with the corner lamp reflectors. I don't recall that as a thing. Maybe I'm getting older and haven't used this truck regularly since 2019.
Fog lamps are fine (new 880 bulbs from Vosla) and all other lighting is doing fine.
I'm thinking it's the diode for the DRLs? Any thoughts on this would be appreciated. Around five years ago the left DRL finally quit and I just left both charred sockets in place with popped bulbs.

you'll probably have to do a little more troubleshooting
check all fuses. (all of them)
check that the drl sockets have a good ground
use a meter
**note that DRL's only come on in daylight while in drive, parking brake not set. maybe verify that the parking brake light works, if not resolve that issue (usually the copper tab contact in the switch way up under the drivers side dash, contact cleaner usually works, not that it has to work in order for the drl's work but more to verify it is working and not stuck somehow and making the drl's not work.

also another thing to check is verifiy the wiring isn't somehow screwy, face a glass window or somewhere that you can see the lights in front, with engine on and in drive in daylight, hit the dome overide button 3 times in a row, if the headlights then turn off you might have something wired wrong

if the dome overide button isn't working that may or may not be related not entirely sure on that one.

you wrote "switch on"...what switch is ON???...for your DRLs (unless your lights are vastly different than my '05 Yukon Denali) the light switch is either OFF (the circle) or AUTO...Daytime Running Lamps/Lights are meant to illuminate when the headlight switch is not activated and your vehicle is in gear...

good luck,

Bill