why does my macbook randomly turns on keyboard navigation

when i type and tap the space key the keyboard navigation option turns on and wont let me type in a space and then even after i turn it off in system preferences it still keeps working.. i dont know how to deal with it but its really annoying bc i cant type in normal texts and its impossible to turn off, except i should wait really long until it turns off somehow, but obviously its vey inconvenient. help me pls:((