Steps to reproduce:
Open Windows Exporer. Navigate to same directory containing .ods or .odt files. Double Click at such a file.
It happens quite often that LibreOffice opens the document, but the Explorer window remains on top of the document. Clicking into visible parts (execpt into the caption bar) of LibreOffice does not bring the LibreOffice in the foreground.
Without any additional action LibreOffice should show the opened document in the foreground. Clicking into the document should bring it to the foreground too. Maybe the two things are related: After the open document has been brought to the foreground at least once, the clicking into the document works as expectet, i.e. brings the document to the foreground. So if LibreOffice would show the document in the foreground when it is opened then the second problem becomes irrelevant.
LibreOffice 18.104.22.168 german, Windows 7
*** This bug has been marked as a duplicate of bug 48300 ***