MSA: writing into activity-note-field always deletes signs at first time

Hello experts,

we use msa50sp6, and we have the problem that when

I start my laptop and then msa and goto an activty-note and want to write further to an existing text, the system deletes the signs of the old text while writing the new one.

When I then press Ins-Key on my keyboard, then I can write

without deleting the old text.

Problem is that I always first have to press the Ins-Key

after starting laptop/msa.

Does anybody know where I can change this behaviour ?

In MS-word this behaviour works correct, it must be a problem of msa.

Best regards

Gerd