Fiskaly Service respons with Error 503, "failed to fetch remote JWK"

[Vento-Nuenenen]

We have seen the following issue recently:

[ERROR] 2021/08/13 08:50:03 auth.go:132: failed to parse organization_id and env from token: failed to fetch remote JWK (status = 503)
[ERROR] 2021/08/13 08:50:03 request.go:227: authentication error: failed to fetch remote JWK (status = 503)
[ERROR] 2021/08/13 08:50:03 request.go:338: building http request error: failed to fetch remote JWK (status = 503)
[ERROR] 2021/08/13 08:50:03 request.go:272: failed to do http request, error failed to fetch remote JWK (status = 503)
[ERROR] 2021/08/13 08:50:03 request.go:159: request error: failed to fetch remote JWK (status = 503)

It seemed, like the issue let the fiskaly-client crash.
At least, it was unreachable for some moments after the occurence.