Can't unlock OEM, showing "Processing" message permanently

Okay, I managed to get the relevant lines from logcat (I think):

06-03 16:57:39.844 2374 2374 D OemLockVerifier: queryVerifyResultGet–targetUrl=https://factory.fairphone.com/api/unlock-codes/Technician’s IMEI/Technician’s serial no./Technician’s unlock code
06-03 16:57:39.845 2374 22105 D OemLockVerifier: queryVerifyResultGet–oem Lock verifier Start
06-03 16:57:39.845 2374 22105 D OemLockVerifier: acquireWakeLock
06-03 16:57:39.846 2374 22105 D OemLockVerifier: mWakeLock acquire.
06-03 16:57:40.518 2374 22105 D OemLockVerifier: WARNING: Hostname is not matched for cert.
06-03 16:57:50.743 2374 22105 D OemLockVerifier: queryVerifyResultGet()–resp_code1=504
06-03 16:57:50.743 2374 22105 D OemLockVerifier: queryVerifyResultGet()–verify_code1=
06-03 16:57:50.743 2374 22105 I OemUnlockPreferenceController: Verify oem lock Result : 504,msg:

So this seems to be related to this thread: OEM Unlock getting stuck on Processing - Server 503 - only that I get error 504 rather than 503. Error 504 seems to be a “gateway timeout”…so I’m guessing I can only resort to contacting the FP support here?

PS I use the NetGear app but of course I turned it off during the whole procedure…