I have checked with my SWARM installation (v3.2.0) too, and I am seeing the same. The only explanation that comes to mind (since we have not changed anything on our side) is that SWARM developers have introduced something that is causing your Shake to not display velocity anymore.
This is an issue we have also had in the past, where some Shakes would correctly display counts (or velocity) when the “Use calibrations” box was unchecked (checked). One of the Shakes that I have still displays counts no matter which boxes I check.
If anyone in the community would like to pitch in, feel free to add your experience and/or possible solutions. The only thing I can advise you to do is to write to SWARM creators at USGS, explain in detail the issue to them and see if they already know this bug and if they can provide you with a solution since it is their proprietary software.
You can do it via the SWARM GitHub account, in the Issues tab high on the left: GitHub - usgs/swarm: a Java application designed to display and analyze seismic waveforms in real-time.
In the meanwhile, if you want, you can use our (in Beta version, but we are working hard to finalize all its feature) DataView page here https://dataview.raspberryshake.org/ to display live (or historical) data from your Shake with velocity units of measure.