Google Cloud Run custom domains in Cloudflare

When trying to add a domain mapping to a cloud run service, I cannot use the Cloudflare Proxied mode. If the CNAME or A records are in proxied mode, my domain mapping is not executed for the Cloud Run service. If I remove the proxy mode, it gets mapped. I can switch Proxy mode back on afterwards.

BUT… I guess, once the Google certificates needs to be renewed - after 3 months - everything will break, because it cannot be renewed because of the proxy mode.

So, is there any way to to map a custom domain to a cloud run domain *.run.app into a custom domain in Cloudflare ? Sort of pass through, or through load balancing, or page rules?

Any feedback welcome!