The current www/chromium (chromium-152.0.7977.75_2) suffers from an upstream bug (which should be fixed in 153.0.8010.47). When launched from a desktop environment (button / menu), it does not switch into the correct scaling mode to react to window move/resize events.
The quick fix while waiting for this to filter down is to launch chrome from a terminal, or to disable "Use startup notification" in the launcher item.
The quick fix while waiting for this to filter down is to launch chrome from a terminal, or to disable "Use startup notification" in the launcher item.