Sketchup doesn't remember assigned shortcuts under some keys

Hi, I noticed that Sketchup doesn’t remember assigned shortcuts under some keys, for example PgUp/PgDn. It works only until the program restart. Is it a bug?

Does anyone know if Sketchup supports mouse buttons other than LMB, RMB, MMB?

That’s done through the mouse driver interface. Even the conventional three are assigned through the mouse interface.

So how can I assign them in Sketchup?

You don’t. You can assign keystrokes in SketchUp and then in the mouse settings, assign those keystrokes to the buttons on the mouse.

On my mouse for example I have a button set to Ctrl+Z for undo.

Can you assign PgUp/PgDn in the Sketchup?

What do you want to assign them to? Did you try that?

Yes, I tried. I want it assigned for example to Camera>Previous or Edit>Delete guidelines.

Looks like Page Down and Page Up are hard coded. If you are going to use buttons on your mouse for these things, you can use some other key strokes that aren’t hard coded. Here I’ve assigned F5 to Camera>Previous and assigned that key stroke to a button on my mouse and it works fine.
Screenshot - 5_23_2020 , 3_52_45 PM

I have assigned PgUp/PgDn in mouse software and I use it a lot for websites and rather don’t want to change it. I also have default Forward/Backward functions in other two mouse buttons (9 button mouse), but also don’t want to change them. I just don’t have enough free keys for these two functions for left hand (whole left keyboard site already assigned). Pitty it’s hard coded. For now I just import shortcuts file every time I open SU (with PgUp/PgDn assigned).