I do that several times, and even restarted several times...
"uncheck" then wait a minute, "check" wait a minute, then uncheck..... and still it keeps going..
It's only 1 proxy source that gives the issue....
And when I delete that proxy source, all found proxy still are in the proxy list....
So I added it again, waited to find the proxy's again, checked off and stopped proxy checker...
But then After 10 minutes my private proxies dissapeared from the proxy list....
So Now I deleted the public proxy source again, and have restarted the proxy checker...
I'll send you the proxy source in PM if that's possible.