Switching tabs causes weird input behaviour in terminal

[sysashi]

I have set ALT+[0-9] to switch to particular tab within hy3, and when I switch back and forth tabs and try to input anything my input gets "multiplied" / repeated, depending on how many times I switched back and forth.

output.mp4

(in the video I only type 1 once each time)
Setting any other keybind for hy3:focustab (for example shift + ctrl + [0-9]) does not have this behaviour