This isn’t necessarily a problem but it is weird. Inbound calls connect fine it’s just the caller never hears a ring before the destination (IVR, announcement etc…) picks up.
Is this on the PBX side or the provider? Is there a setting in FreePBX to force a ring to be played to the caller prior to routing the call to the PBX destination?
If it’s really something you want or need, you can direct your inbound route to an announcement that rings a bell, then directs to your IVR or announcements.
It’s not all that unusual, unless you’re used to living on the older PBX or POTS equipment. SIP signals that the connection is ready to go and, if there’s no delay, there’s no ring.
Playing ringing wastes the customer’s time and does nothing for the company. The only benefit is it gets the customer’s attention so he’s sure to correctly hear the options. A brief introduction in the announcement is IMO a better choice. For example, “Thank you for calling Acme. (1 second pause) For sales, press 1 …”