Tuta is a farse.
They don't care about your privacy. Probably Honeypot

Tor Browser - standard settings
Tuta Mail

Seems like your browser is not supported or outdated. Please see FAQ entry for more information
https://tuta.com/faq/#browser-support

Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0
Error: Unsupported
execute@https://app.tuta.com/app.js:1:75817
i@https://app.tuta.com/polyfill.js:1:4214
P@https://app.tuta.com/polyfill.js:1:4183
x.import/</t.C<@https://app.tuta.com/polyfill.js:1:3651 

 Protonmail - I've tried to create a new account - ca. 30 min of tries.

https://account.protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion/signup

"Verification
No verification method available"

Or

Temporary e-mails don't accepted.

Protonmail=honeypot