I enabled HTTPS but it does not work. 400 error

[x38649]

I enabled HTTPS, but it did not work.
but HTTP worked

No error has occurred in the application and it has not reached the application

Examining the packet on the interface confirmed an interesting packet.

Cloud flare is sending an HTTP request to port 443.

It has something application returning error number 400.

I saw my application runninglsof -i: 443
However, the above packet has not arrived in my application.
I use Go language and Echo framework
Echo returning 400 error?

How do I

[sandro]

I presume your SSL mode is either Off or Flexible. Can you confirm that? If you want HTTPS requests it should be one of the Fulls, preferably strict if you have a valid certificate.

[x38649]

Thanks for the reply.
After checking SSL mode it was Full.

After changing SSL mode to Flexible, it was able to access by HTTPS.

Thank you!