Just an alert. Short story: If you lose all but one trunk for "no reason", check your license details. Do not believe the dashboard's display, click on the license in the dashboard, then click Refresh License Key Information at the top of the License Settings page. Long story: After bringing a PBX Express switch up on Google Cloud Platform, licensing 3CX for Standard 4SC, I added the three trunks we need and all went great! For three days the system ran perfectly. Overnight two of the three trunks dropped off. No email from the system advising of the trunk registration change. I looked at the provider's portal and saw that the last registrations on the two dead trunks were a couple of days ago. I confirmed with the trunking provider that they aren't receiving registers from me. I thought I had some level of support, ha ha, $500/yr. Never mind, we're a small business. So I decided to delete a trunk and re-create it (if all you have is a hammer, everything looks like a nail). Woah! It said I couldn't re-create the trunk because "the PBX edition has a 1-trunk limit". On the dashboard it is showing Standard Annual. WTF? I clicked the line Standard Annual on the dashboard and it brought me to the License Settings page and I discovered that it had reverted to PBX (again the dashboard was showing Standard!). I clicked the Refresh License Key button and bingo, the remaining dead trunk connected. Then I recreated the one I deleted and it immediately registered. By deleting that trunk I invalidated four "convenience dialing" Outbound Rules, but they were still there, just mapped to BLOCKED, so I changed them back to the new trunk. We're back on the air. A couple of days ago, then, the license on this switch spontaneously changed to PBX (free) while it was showing Standard Annual on the dashboard. Do not believe the dashboard.