You need the Openvox Drivers, go to the Openvox site and check their wiki for installation instructions. The difference is that Elastix had a partnership with Openvox and the distro had the drivers installed by default but FreePBX doesn’t.
That card did not require patches I woudl assume. But all newer openvox cards require DAHDI to be patched so you will need to follow their guide on that.
Ditched OpenVox for ISDN30 (PRI) for Sangoma Card now and same for ISDN2 (BRI) although B400 OpenVox is a clone of Digium card and works fine. But Sangoma won us over as its low profile card so fits in HPE Gen 10 Microservers