[Bug] New GUI v2 - AC Load (ET112 via RS485) watt value freezes after ~15 minutes

[Fredb45]

Venus OS version: v3.71 (build 20260315163256) Hardware: Cerbo GX (early 2023) GUI: New GUI (gui-v2) on HDMI display Regression since: v3.70 (not present in earlier versions)

Setup

• Cerbo GX

• Multiple Quattro II in parallel (single phase)

• Multiple MPPT RS charge controllers

• Pylontech LV Hub + US5000 batteries

• Carlo Gavazzi ET112 energy meter via RS485 (/dev/ttyUSB0), configured as “AC load” role (Settings → Integrations → Energy meters via RS485)

Bug description

After switching to the new GUI (gui-v2) on the HDMI output, the AC load watt value (text) freezes after approximately 15 minutes and never updates again.

However:

• The blue arc/bar next to the AC load value continues to fluctuate normally, reflecting actual load changes

• Battery values (SOC %, voltage, current) continue to update normally

• PV production values (W) continue to update normally

Only the numerical watt display for the AC load (ET112) stops refreshing. The underlying data is clearly still being received by the GX (as proven by the animated blue bar), but the text binding appears to break.

Evidence

I captured 4 consecutive screenshots over a 3-minute window (07:27–07:30) while deliberately turning appliances on and off to vary the load:

Time	PV (W)	Battery V / A	AC Load (text)	AC Load (bar)
07:27	288W	48.90V / -40.0A	5480W	varies
07:28	312W	48.90V / -81.3A	5480W	varies
07:29	289W	49.01V / -5.3A	5480W	varies
07:30	533W	48.86V / -116A	5480W	varies

→ PV, battery voltage and current all change as expected, the blue bar changes, but the AC load text stays stuck at 5480W.

Key observations

1. Regression: This bug did not exist before v3.70. I had been using gui-v2 since its official release without this issue. Since v3.70 introduced this bug, I had to switch back to the legacy GUI.

2. Still present in v3.71 (build 20260315163256).

3. Legacy GUI (gui-v1) is not affected — the AC load value displays and updates correctly.

4. The bug may be specific to configurations using an external energy meter (ET112) in “AC load” role via RS485, which could explain why it hasn’t been widely reported.

Expected behavior

The AC load numerical watt value should update continuously, just like the blue bar does and just like it worked in gui-v2 before v3.70.

Steps to reproduce

1. Connect an ET112 energy meter via RS485 to the Cerbo GX

2. Configure it as “AC load” role

3. Switch to gui-v2 on HDMI output

4. Wait ~15 minutes

5. Observe that the AC load watt text value stops updating while the blue bar continues to reflect actual load changes

*Photos attached showing the frozen value across 4 consecutive captures.
*

[jeroen]

@Fredb45 Can you check what happens “Display off time” is set to never in Settings → General → Display & Appearance?

[Fredb45]

Hi Jeroen, I don’t see any “Display off time” option in Settings → General → Display & Appearance (see screenshot attached)

[jeroen]

@Fredb45

@Fredb45

I don’t see any “Display off time” option in Settings → General → Display & Appearance

I see and that is actually correct, since turning a generic HDMI screen off is not supported. The New UI incorrectly believes the screen has been blanked though and stops updating (some) values. This will be fixed.

[Fredb45]

Thanks Jeroen, that makes perfect sense. Looking forward to the fix. In the meantime I’ll stay on the legacy GUI.

[ceejm1 (James Mitchelmore)]

Hello,

I think I am seeing the same issue. Cerbo on 3.70. HDMI taken to an external display - not the GX touchscreen.

The total grid/solar/load figures ‘stick’ after circa 15mins. The per phase figures fluctuate and follow a web view of the remote console as expected.

Any workaround to nudge it to wake up?

Cheers

James

[lxonline (LX)]

Try set the screen to always on?

[ceejm1 (James Mitchelmore)]

Thanks,

As the comment earlier in the thread, I don’t see that option in the settings. It was noted that its because its a generic HDMI screen.

Cheers

James

[jeroen]

@Fredb45

Looking forward to the fix

v3.72~1 should fix this.

[patssle]

I found this thread through Google search. Also having the same issue after updating today. So just wanted to throw another hat into the ring of another user waiting for the update fix. Thank you!

[jeroen]

If you install the current beta it should no longer happen.

[Fredb45]

Hi all, just confirming that v3.72 fixes this issue. The AC load watt value on the HDMI display now updates correctly in the New GUI. Thanks Jeroen for the quick identification and fix! Switching back to gui-v2. This topic can be closed.