URGECT HELP REQUIRED: Delete a note and the whole pitch material moves

Hi - I urgently need your help. When I delete a whole measure (or extend or reduce the value of any note) and WHOLE pitch material moves. If I delete a bar the pitch material jumps back to fill that bar. This is impossible to work with.

I cannot find anywhere in settings why this is happening and it’s just started. I urgently need this fixed. Please can someone help?

You have insert mode turned on. Press “I” (the letter i) to turn it off. You can see the blue box on the left panel turns off.

try toggling the insert key.

Thank you SO much!