v3.5.0 very slow or failing multi-topic line chart on RPi3B/+

[samosss]

Since deploying v3.5.0 on RPi3B/3B+, rendering of a chart that has multiple topics in a line chart uses much more time to load (and most times doesn't load) when running the browser on RPi and VNC remoting in. (Worked fine for two years prior to updating to v3.5.0)

What are the steps to reproduce?

Deploy v3.5.0 on an RPi 3B/1GB, when accessing the RPi remotely using RealVNC / Cloud.
Add flow which updates Line Chart with three topics, and a data point for each topic, every two minutes. Configure the chart to show the last 6 hours of data. After a few minutes, open a browser on the RPi using Firefox ESR or Chrome and navigate to the tab with the chart.

What happens?

Mostly, the tab never completes rendering / never presents the chart.

Other observations: Four Column charts on another tab are okay (but also slower on 3.5.0 vs 3.3.x)

What do you expect to happen?

Perform approximately as per v3.3.x, which took say 2-5 seconds to display on the same setup.

Please tell us about your environment:

• Node-RED-Dashboard version: 3.5.0
• Node-RED version:3.0.2
• node.js version:16.20.1
• npm version:8.19.4
• Platform/OS: Raspian Bullseye
• Browser: Firefox ESR 102.11.0esr or Chrome (latest)
• Locale En/Australia UTF-8