Getting "CNAME Cross-User Banned" using Cloudflare for Saas and r2 with custom domain. We have: 1. r

Getting "CNAME Cross-User Banned" using Cloudflare for Saas and r2 with custom domain.
We have:
  1. r2 bucket with 2 custom domains https://developers.cloudflare.com/r2/buckets/public-buckets/#custom-domains-configuration assets.webstudio.is and assets.wstd.work
  2. Worker as SaaS fallback origin https://developers.cloudflare.com/cloudflare-for-platforms/cloudflare-for-saas/domain-support/worker-as-origin/ with dispatch namespace inside placed on route */* at wstd.work zone
  3. Worker route service for assets.wstd.work/* is set to None to bypass 2.
  4. DNS Entries for SaaS with
    proxy-fallback A 192.0.2.1
    *.customers CNAME proxy-fallback.wstd.work
Now if inside worker for SaaS fallback origin we have the following fetch
await fetch(`https://assets.wstd.work/some-resource.ext`, request);

The fetch above fails with "CNAME Cross-User Banned" Error 1014

BUT if we change fetch onto
await fetch(`https://assets.webstudio.is/some-resource.ext`, request);

Everything is OK.

I think that its a bug, as both domains are on same account, we are using cloudflare for SaaS, and access to assets.wstd.work must not be prevented

Important detail, the fail is reproduced ONLY if customer domain is placed on cloudflare.
And has PROXY enabled on route.

So our customer with poke-method.work domain
Has DNS entry on Cloudflare poke-method.work CNAME customer-id.customers.wstd.work with Proxy flag enabled

No issues with disabled Proxy flag, no issues with providers like Namecheap, only if customer provider is Cloudflare itself
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