I'm also having this exact issue. I have also tried many things including rolling back the MbedOS, updating Wifi firmware.
Notably, I have tried the QSPIFormat Example in Arduino IDE (which appears to execute without issue) however if I try the memory formatting tutorial (described in this forum post * https://forum.arduino.cc/t/opta-sill-not-connecting-to-plc-ide/1230775/25.) I find that the program fails with the flashing red light on the OPTA after the "Erasing the QSPIF..." stage. The next stage is formatting the Wifi Partition so can only assume ther's an issue writing to this part of the QSPI?
I found another post about the QSPIF entering a read only state due to an internal pin going to a low state and failing in that position permanently unless is manually written to. But would expect this would also prevent the QSPIF being erased as well and throw an error as part of that part of the program...
(unbrick-recover-readonly-flash-arduino-opta/unlockOptaNORFlash.cpp at master · ddmesh/unbrick-recover-readonly-flash-arduino-opta · GitHub)
I'm seriously at a loss now and concerned my OPTA is bricked. If there is any experience out there I would appreciate some pointers!
PLC IDE 1.0.8
Arduino IDE 2.3.4