I can't see questions you asked with downvotes , which probably indicate the problem is with deleted post you have.
It's not a problem to have deleted posts. But if a large percentage of your posts are deleted by yourself or the community, then apparently they were not suitable for the site. But meanwhile they might have wasted time from users who read them, or even responded to them. Therefore deleted posts have an effect on the filter, among many other secret factors.
Another option, you got proximity 70 answer out of 90, with zero upvotes, which may indicate a low quality post.
If you really want to know what is the reason for the block, and what you should do, contact the stackoverflow team..
yes I have deleted some questions, because after posting, i can find the answers within 5 mins. so i gave upvote to that answers and deleted this. I was not aware of this may affect my rights to ask question here...
So it's probably the first option like I thought, maybe undeleting the questions can help.
We can't be sure what is the reason or how you should fix it because:
- The blocks factors are secrets.
- Only moderator can see deleted posts, and the amount of flags your account "gained".