CTRL + S

...solved it for me AFTER using...

stty -ixon
If CTRL+S doesn't work for you is because according to Vincenzo Pii's accepted answer in another related thread:

The problem is that this binding, in many terminals, is used by default to send the pause transmission code (XOF).

As in man stty:

[-]ixon
    enable XON/XOFF flow control
So, if you have this option enabled on your terminal (the output of stty -a contains ixon withouth the - sign in front), you cannot use CTRL+S in the context of reverse-i-search.

To disable it, use the following command:

stty -ixon
And CTRL+S will give you a (i-search) (non reverse).