Apple Magic Keyboard 2 malfunctions in mac OS Catalina

Recently, on 11th July,2020, I bought new Apple 21.5 inch iMac ,retina display which came with mac OS High Sierra operating system. Both bluetooth devices ( Apple magic mouse 2 and blue tooth keyboard 2 ) worked perfect. Thereafter, on 15th July,2020 I upgraded to mac OS Catalina. Now, I find that under mac OS Catalina, bluetooth mouse works perfectly well, however, bluetooth keyboard malfunctions and due to which some alphabets such as K L , N M and some numerals such as 7 8 9 are not registered when their keys are pressed. I took the keyboard to authorised repair shop who tested on Apple iMac running on os High Sierra and it worked perfectly ok. So ,the problem is that mac OS Catalina may have bugs in operating part or in bluetooth patch. Please offer suggestion/ solutions to remedy. Ramesh Goradia. friday,31st July,2020.