Just got the s3 error when trying to submit a bug. Worked on second attempt with the same data and browser. Never have seen this error before. May not need any action, but better to tell you in case this becomes a problem.
Browser is a cromium derivate:
|Vivaldi||3.1.1929.34 (Stable channel) (64-bit)|
|OS||Windows 10 OS Version 1903 (Build 18362.836)|