How to not get a [WARNING] Could not diagnose if domains are reachable from outside in IPv4.?

My YunoHost server

Hardware: AMD 64
YunoHost version: 4.3.6.3
Are you in a special context or did you perform some particular tweaking on your YunoHost instance ? : yes
If yes, please explain:
VPN

Description of my issue

[WARNING] Could not diagnose if domains are reachable from outside in IPv4.
 - Error: Diagnosis request was refused: b'{"error":{"code":"error_bad_json_data","content":"Invalid request: You cannot test that many domains ......Original request body was: b\'{\\"domains\\": [\\ HUGE LIST OF DOMAINS], \\"nonce\\": \\"somestringmaybeimportanttokeepprivate?\\"}\'"}}'

This, can this be patched or split up somehow?

How many domains/subdomains are added in your ynh ?

plenty

But what does it matter?