I haven't had any trouble with 1Blocker. Have you contacted the developer?At first everything was great. Then some time later i got beachballs from time to time in Safari - noticed most happens on my work's website. Thought it is bad site code, until i started getting beachballs somewhere else.
Finally suspected 1Blocker and uninstalled it. Surprisingly now safari opens websites even faster than before with 1blocker. No beachballs for now, have to check that for some time.
Though, youtube ads would annoy me.