Hi, please make sure you report this as a bug to Line 6. You're not the first one to report this, even on firmware 2.92. (Is that the firmware you're using?) If they aren't aware, it won't get fixed; and if they get the report from many, it'll get a higher priority. Here's a direct link to submit a ticket, only takes a couple minutes: https://line6.com/support/tickets/add.html If you can figure out a way to reliably reproduce it (it might be triggered by certain presets on your Helix), that will be hugely helpful in getting them to fix it.
FWIW, firmware 2.90 and 2.91 added the new meters for input, output, and compression, but there was some kind of bug introduced that would make the meters and tuner lag. In 2.92, they improved it somehow, but under certain conditions the metering lag still happens. I found a way to reliably reproduce this in minutes and submitted it to them, and they've confirmed awareness, but I'm not sure if they know the tuner still has issues too.
In the case of the lagging output meters, I can trigger it by changing to certain presets after Helix is powered on for a while. If I stay on the same preset it booted into, it's fine, but once I trigger it by going to another preset, the lag quickly grows over about a 60 second interval and remains until a reboot. At first it appeared that a full factory reset fixed it, but I've proven that to not be true.
Here's another recent post with the same issue: