drivers – Laptop keyboard typing + on its own

I am using an HP Laptop with intel core i5 (8th Generation) and 8GB RAM. My OS is Ubuntu 20.04 LTS. Recently I am facing a strange issue. Whenever I am trying to type something, my keyboard is typing ‘+’ signs on its own. And it’s kind of unstoppable. I have to repeatedly press the backspace in order to delete them but it keeps on typing. It is highly frustrating. I am unsure whether it is due to a stuck key or a faulty driver. I tried with an USB keyboard but could not understand properly, because both the embedded keyboard and external keyboard are active and therefore, it kept on typing ‘+’ as usual.

Is there any way to stop this issue? How can I change keyboard driver or at least understand what is causing this problem? And also, is there anything like keytweak which I can use on ubuntu?