Upgrade from 2.3 to 2.4.5 and LetsEncrypt stopped working

With the previous version Traefik was working as expected, with this new one I am getting this error:

time="2021-02-19T17:10:54Z" level=error msg="Unable to obtain ACME certificate for domains "MYDOMAIN.COM,www.MYDOMAIN.COM": unable to generate a certificate for the domains [www.MYDOMAIN.COM]: error: one or more domains had a problem:\n[MYDOMAIN.COM] [MYDOMAIN.COM] acme: error presenting token: timeout 2021-02-19 17:10:49.516475109 +0000 UTC m=+138.399723794\n[www.MYDOMAIN.COM] [www.MYDOMAIN.COM] acme: error presenting token: timeout 2021-02-19 17:10:52.892029691 +0000 UTC m=+141.775278389\n" routerName=heimdall@docker rule="Host(MYDOMAIN.COM)||Host(www.MYDOMAIN.COM)" providerName=default.acme

I noticed there were a few changes to the certificate creation, but I didn't see any mentions of changes to the configuration files. Have I missed something?

Don't know if it's related, but in my case the acme.json file is cleared of previous certificates everytime I need to restart traefik.

Getting the same error from traefik on new certificates issuing using TLS challenge.
Seems 2.4.x is to blame.

Hello,

I recommend increasing the throttleduration

https://doc.traefik.io/traefik/v2.4/providers/kubernetes-crd/#throttleduration