Can't decrypt message sent with Protonmail

[akanashiro]

Hello Community:

I have managed to configure my pgp and send encrypted and signed messages to a Protonmail account without any issue using Vivaldi webmail client.

Unfortunately I couldn't achieve the same test sending an encrypted email from Protonmail. Vivaldi webmail shows me this message: "Decryption failed. Private key not found. Key ID: 4BD2C599".

This is strange because I have imported my Vivaldi public key to Protonmail.
Should I need to configure one more thing?

Note: haven't tried this in a email client like Thunderbird yet.

Thanks in advance.

[akanashiro]

I tried the same scenario with Thunderbird creating pgp keys and could use encryption succesfuly.
I guess Vivaldi webmail is unable to decrypt or maybe I am missing something.

[akanashiro]

@Gwen-Dragon thanks for your quick answer.
Yesterday I did another try and created a PGP (RSA 4096) of my vivaldi account using Thunderbird 78 built-in PGP tool and then uploaded the respective keys into Protonmail and Vivaldi.
Doing that, encryption worked fine between Protonmail and Vivaldi Mail.
I will try to reproduce the initial scenario to open a bug and write a doc of the workaround.
Regards