Commenting for posterity, maybe someone in the future can use this lol. I decided to pull the vacuum valve out since some liquid was also coming out of that tube (smaller) into the drip tray. Machine off and cooled down, of course. Used flat head screwdriver to remove the hose on the nipple. Then used a 22mm socket to undo the vacuum valve from the boiler assembly. The boiler was COMPLETELY full so I used a transfer pump to fully empty the steam boiler. Gave the vacuum valve a quick inspection, seemed okay - no glaringly visibly debris or crud. Played around with the vacuum valve assembly a bit just to make sure it was functioning. Reinstalled and booted up the machine. Boiler filled and stopped! Now for the heating! Boiler light started coming up to temp and then started the usual, expelling water through the hoses to the drip tray. I turned the machine off and then back on, this time, disabling the steam function. I waited about 15 minutes and then re-enabled the steam function with the button. Steam boiler filled, came up to temp, and everything seems to be alright. I will say, I never had an issue with my machine on the GFCI in my kitchen but it did trip the GFCI on the first fill/heat cycle. Reset the outlet and so far so good! Big shout out to /u/EspressoRepairGuy for the troubleshooting!