I am setting up for a client using a hosted instance of 3CX (ESXi not PBX Express) with 4 remote sites connecting via SBC. PBX is current version (SR3) and has a public IP (no NAT). SBC is version 15.5.7467 running on Debian 9. Each SBC config is the default as created by the install and is working (in isolation) with all calls/blf/etc working. The problem is that as soon as I connect a second SBC to the PBX, all extensions fail via SBC fail. In testing I have SBC1 setup with two phones connected and working. Within several minutes of starting SBC2 (with or without phones connected), phones on both SBCs fail with "No Service" fail. At that point, stopping either SBC sees the other recover. I have tested this against several PBX instances all with the same result. Can anyone confirm current use with more than a single SBC connecting? Can anyone offer suggestion relating specifically to using multiple SBCs?