If you have a Hologram Verizon SIM (staring with 893) that is stuck in fail over mode (able to connect to AT&T/T-Mobile/international carriers), you can manually trigger a failback by connecting to Hologram and then turning on Airplane Mode for 15 minutes. You will see the SIM provider change from "Hologram" to "Verizon".
If you want to go the other direction, you can do the same to get from Verizon to Hologram