I have installed tryton-5.0.22 and trytond-5.0.18.
I have config ca_certs and test with requests.post(…, verify=ca_certs) and all works fine (I have correct response).
On tryton Gtk client I have host myhost:443 and response ERROR:tryton.rpc:<Fault ‘400’: ‘Bad Request’>
If you are using a custom CA, you must configure it in ~/.config/tryton/x.y/ca_certs.
If you have used/connected first to the server without ssl, you should also clean the ~/.config/tryton/x.y/known_hosts.