In last year ebay block my acount by changing password mostly weekly. Probably due to instant using Myibidder (I make 20-40 bidds daily). Does anybody check if it depends upon used national site for snipering? Which site (available option in settings) is better to use? I fill ebay.de more often block account because of using sniper.

I don't think this is related, but it's worth to try something else. Each account could be different.
Some users reported that creating a brand new eBay account for sniping purposes may help too.