LEDs, Resistors, Flashers - Should I just give up?

[A97obs]

I thought we needed another thread on LEDs. I think I've read all of them on this forum, YouTube, and the whole Internet. Everything almost works, but not quite: the side markers aren't working right.

The problem:
When the parking and/or headlights are turned off:
- with the key in the run position, the turn signals and hazards are not visibly operating on the side marker lamps but fine on all other lamps
- with the key in the off position, the hazards are very dim on the side marker lamps but fine on all other lamps. See here:

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The facts:
I do not have a hyper-flash problem.
Electronic, no-load LED flashers were installed for the turn signals and the hazards.
Ground attachments G101, G104, and G105 (the parking and side marker lamp circuit grounds) have all been cleaned and sanded. (They were already very clean.)
All interior and exterior lights other than the headlights have been replaced with LEDs (switchbacks in the four parking lamps) including the dash which of course includes the turn signal/hazard indicators.
Everything works perfectly with incandescent bulbs.
Everything works perfectly when the parking lights and/or headlights are on.
Everything works perfectly if just one LED switchback (in any position) is changed back to an incandescent.
I have tried numerous flashers and switchbacks.

I added resistors. Nothing changed.

What's the problem with the side marker lamps?

Additional information:
I noticed the wires going into one of the parking lamp sockets has been tapped in to. The wires are exposed in a small area.
I sometimes have to turn one of the switchbacks back/counter-clockwise to get it to light, just a millimeter or so after installing it.
One of the side marker lamp sockets seems to have a temperamental connection and I have to adjust/wiggle the bulb to get it to light.
The two issues above are not persistent or consistent.

GIFs of hazards with lights on and off:
Lights on:

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Lights off:

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Note the switchbacks flash a bit brighter when the lights are turned on.

Might you have insight on my issue with my post .
I have perfect working rear tail and front parking LEDs
I added a set of the LED corner side markers that direct plug into the 194 socket and I get a solid light on all the corners and front parking lenses with the headlight switch turned on.
If I shut the headlight switch off the corner LEDs blink with the parking lamps . Soon as I turn on parking lights or all the way to lights On”
All the lights up front light up solid “Zero” indication of blinking.
I tried to flip the led marker plug in for polarity still solid Lit .
I know the LEDs work cause they blink fine with the headlights switch left (Off)