I based my current app on tabs too, and in fact there are strange bugs, tabs sometimes confuse each other with variables and such.
Like if you try to push a new page from a tab (like a child page), it won’t work well with back button disappearing. This is a known bug since one year, and repeateatly closed as “solved” on Github.
My advice: Try to avoid tabs if possible, I changed my navigation design to use segments and modals more. It works quite well inside tabs. Below link on how to use segments.