Label editor in Wizard very unresponsive after some usage

[henning]

As the default proposals for labels are not entirely visible (e.g. for "Amp Decay" i see only "Amp") there is some editing necessry on the labels.
While some first labels can be edited relatively easy in the editor, after a few minutes of usage and getting to the third or forth entries or so, the wizard gets extremely slow on the Label editing page.
That means, each keyboard input takes up to 10s to result in a change in the html form and then in the displayed interface result.
It makes this editing task pretty difficult/time consuming.

I'm on Ubuntu 21.10 and tried with firefox 95.0 and Chromium 96.0.4664.45 - both same behaviour.
Is there anything I can try to improve this?