Sounds like the PLA may have swelled in the hotend from heat creep… How much of the filament is still in the extruder? Any chance you can heat the hotend up past the PLA temp and push a bit of the filament through? Just need to push maybe 10-20mm through the nozzle to clear the swollen filament, and then you should be able to pull the filament out.
Other option is to heat up the hotend, remove the nozzle and push the filament through… I don’t think LB supports this, but its fairly easy to pull the nozzle off. Heat the hotend past 165C, use a wrench to hold the heater block and another wrench to unscrew the nozzle. To reinstall, heat the hotend past 165C and finger thread the nozzle… then wrenches to tighten at a hotend temp of 250C. Keep in mind the brass nozzle is soft, so make sure not to damage the thread.
The root cause of this may be a bad heatsink fan. Check that its running and make sure to point it down a bit so the air is hitting the thicker heatsink near the heat break.
You’re on the right path in contacting support.
On another note, clamping forceps help with gripping the filament if its past the hobbed bolt. Undo the idler, grip/clamp the filament, heat up the hotend, and pull on the forceps. Great for when the filament spool runs out…