1 hour before bid all amounts for bids were still in Myibay.
I could not monitor application and was not at PC but after auctions ended I saw all my amounts disappeared from Myibay.
Despite it one out of 2 auctions I won and another I lost. My bid was higher that winning bid but Myibay did not even bid on it.

I also noticed that out of 7 lots that not completed yet (ending tomorrow) and were already set for bidding 4 amounts disappeared and 3 left intact.

Why ? I cannot figure out. It happened before too.

You did not include any item numbers in question so I can't check.
But it sounds like you set a Group with limit 1 item to win, so Myibidder cancelled all other snipes after you won your first item:
https://www.myibidder.com/login/faq/2/#q10

You need to either make sure you don't use the Group feature, or set another limit (or remove the limit at all).

Yes. I think you are right.
I did not realized that I need to set limits

But if I want to win all items in specific group, how can I setup limits for "All" ?
Is it possible to set limits for group on website ?

I believe you have to put "0", which means no limit.
You can also set a default number of wins per group in the Profile on the website. That will affect all future groups.

I think it should be not "0" but "all"

"0" means "all". It should be also stated in the Windows application.

No. In Windows application it says:
Group bidding.
Default "to Win" <box to put number> (Empty for "all")

Yes, you can put empty too. Either one will be fine.
But this option will affect future groups only. The current ones need to be re-created or changed individually.

yes. I already adjusted that.
Thank you for help