Nat is absolutely correct for many VP releases. However, PNG image placement behavior has changed in recent 10.x versions...
A PNG image should land where desired via the right-click menu in the bin or the ADD button, or by dragging it to the track.
APNG transparent videos may have the behavior you describe if the OPTIONS | EDITING menu box at the bottom - "automatically add overlay videos on overlay track" - is enabled. That option may not be available in all versions.
ZaneCzora, please state what kind of file is causing problems. Better still, share it...
Upload the file to a free server, such as Google Drive or MS OneDrive, get a shared (public) link, copy the link and paste it here or to me in a Private Message via the mail envelope in the top-right corner of this forum. When using Google Drive, if necessary change "restricted" to "anyone with link can view."
