Thanks for the report. You came across a genuine bug: the main window was being resized to a fixed default width every time it was shown, which is why it reset on launch, on a language change, and also when restored from the tray.
We have just fixed this small oversight. Please download the
latest build and install over your current version. It now remembers the size between runs, along with the column widths. The position deliberately isn't remembered because monitors get connected and disconnected, and a saved position can leave the window off-screen, so the window deliberately always opens centred.