Raspberry Pi 4 Lag

Hi all,
I have installed the PlanetCNC TNG software on a Raspberry Pi 4B with 4gb of ram using Raspbian and following the tutorial for installing on a Rasberry Pi 3 on the PlanetCNC blog.
Unfortunately it's not usable as there is so much lag on the interface. There is a 2 to 3 second lag between clicking on the interface and something actually happening.
The raspbian desktop works fine with no issues so it's definitely just in the TNG software.
I have ramped up the amount of ram dedicated to the GPU to no avail.
Perhaps I'm missing some setting somewhere?
Any help is appreciated.
Thanks

Strange. It should run without any lag. Did you check CPU utilization with htop?
Do you have proper cooling for RPi4? It gets very hot without good cooler and then CPU is throttled back.

Hi,
Thanks for your reply. I haven't actually checked with htop. I will do so now.
I do have good cooling though. Using a heatsink and fan in a case.

Hi.
Had similar issue. Not as long lag, maybe around 0,3 seconds, but still very annoying.
I use a 4K TV, so the resolution was automatically set very high from the start.
In my case the lag disappeared with lower resulution setting to the TV.