GoogleTTS Missing service configuration

Starting from 3.2M5 and now 3.2 release.

My google TTS would work when I restarted openhab, but after a while, it stopped working with this error:

2021-12-22 16:05:11.068 [WARN ] [ce.googletts.internal.GoogleCloudAPI] - Error initializing Google Cloud TTS service: Error fetching access token. Invalid authcode? Please generate a new one.

Then if I restart openhab, without regenerating any keys for google tts, it would work… for a while (less than a day) then it would stop working again. Each time, restarting openhab would make it work again.

My google tts has been working reliably since February/March 2021. I was using 3.1, 3.2M1 → M2 → M3 → M4. Then starting from M5 it started playing up like this.

My oauth is set to production and external.