problems w/ note input per keyboard

hello,

often note input per keyboard does not work... sometimes just for certain notes, but for the others i always have to click per mouse... e.g. b & c i can do per keyboard, but all others per mouse click. sometimes i can though. it seems to change per time that i use the program.
also i can not activate note input itself per keyboard, only per mouse click (also sometimes yes, sometimes no).
i work on a macbook 10.13.6 and my musescore version is 3.6.2.5

thanks a bunch!
and just saying - i love musescore!!
:-)

sanne