Yes, you can mix and match drivers if you want. Remember that each will use a different bind port and you must be careful which driver uses which port when setting up registrations.
Try these pjsip trunk settings, based on my very limited experience with 3CX. If you have trouble, at the Asterisk command prompt, type pjsip set logger on
make or receive a failing call, paste the Asterisk log for the call at pastebin.freepbx.org and post the link here. If the trunk won’t register, paste the log of a registration attempt.
Also, paste a SIP trace from 3CX, showing the same function (registration, incoming or outgoing) that is not working in FreePBX
Username: +331648XXXXX
Auth username: (same as ID in 3CX)
Secret: (your SIP password)
SIP Server: orange-obs.fr
Outbound Proxy: sip:pcscfgm.orange-obs.fr\;lr\;hide
From Domain: orange-obs.fr
From User: +331648XXXXX