All window power goes to the passenger's window switch located on the driver's door. From there it goes two directions - it jumpers to the driver's window switch, and it also goes back into the frunk and across to the to the passenger's side switch. There are white circular connectors in the frunk near the front edges of the door. They house the power window wiring. You can wring the wiring out there probably easier than opening your doors up if it gets to that stage.
I would gently pull out the passenger's switch on the driver's door and carefully check power (in and out) there. That will tell you if your switch is working properly. Looking at the passenger's switch on the driver's door, the incoming power is Red/Blue (switch pin 5 and jumpered to pin 3 then to the driver's switch pin 5. Red/Black on pin2 and Red/White on pin 1 are the outgoing power to the switch on the passenger's door before it makes it way to the motor . One of them will have power on it depending on which way you are commanding the window up vs. down. Use a local ground at that door, or the brown wire connection at pin 4 of the switch if you can, to check the operation of the switch.
I borrowed these photos from some nice person on this site:
Then I would do the same at the switch at the passenger's door. Here, when the Red/White carries power at pin 3 it will exit the switch to the motor on Blue wire at pin 1. When the Red/Black wire at pin 5 carries the power, it will exit the switch at Blue/Black pin 2.
The ground probably isn't the issue based on your description because there are separate grounds closer to the door and would only affect that door switch.
Based on what you read at each switch you will give you an idea of where your issue lies.
If it isn't the switches, then the next step would be to check wires. Those circular connectors make it relatively easy as they isolate the wires near and in each door and the wires across the funk. More than likely, if it is a wire, it is door related. Mine were corroded inside the door but I would imagine that the wires also get worked every time you open and close the door and could cause an issue over 30-ish years.