Antwort auf: Philips: Neue Firmware für 2019/2020er TVs mit Android TV 11 (TPM191E: 201.0.248.217)
@Mike:
fom my point of view, you can downgrade to .178 at any time - "despite your Brexit" (forgive my mockery) - using the upgrade loader available here in the forum. But you have to use the upgrade loader variant. You will have your reasons for not wanting to use the current ATV 11 firmware.
I'm not familiar with the .186, which was, as you said, apparently only available in the UK, so I can't tell you how this firmware differs from the actually stable .178.
Be sure to do a factory reset after the downgrade.