wordfence causing 500 and 503 errors

Hello
I wish to thank Wafalla, the wordfence author for his answer to my problem. Because i have managed wordpress, I wasn’t able to put the sites on temporary debug mode so i asked my hosting support team to do it for me. And they found nothing, at the debug logs that could explain why, exactly when i activate wordfence, at least half of my HTTP go down, as seen at host-tracker and this on an intermittent way, that is, in one minute they are up, in the second they are down and go unstable all the time. So, the facts are these: deactivating all plugins , my sites are up with no issues; activating wordfence, the problem begins; deactivating it again, both sites are ok. None of the other plugins I have made this effect although there is some trouble also with Jetpack because comments don’t publish getting a 404 error and neither related posts. the fact is, since the last wordpress update, the sites stopped from working normally like before. And no one finds a cause to explain why I can’t install wordfence, my preferred plugin, not counting with Jetpack, that is a full pack of functions. My hosting says that finds nothing in their logs that could create this on their part. And if the debug doesn’t show any error connected with the plugin should i conclude that this effect has no cause?! There must be a condition that creates this effect. If someone can explain it, would be awesome . Thanks