This issue continues into V6.011. If the option "Set tray icon to Italic until first weather update" is active, WWL will open italic, then change to normal for about 2 seconds and revert back to italic. Manually retrieving the weather will stop this behavior; however, it may take 3-4 attempts to do so.
For example, on this morning's system startup, the temp first displayed italic 32 degrees....then promptly switched to normal 38 degrees...and 1-2 seconds later changed to italic 38 degrees. Two manual retrieve weather attempts converted it back to normal 38 degrees. I've never seen it convert back to italic once this initial flurry ends.
The pic below shows my current settings...which does not create the issue because the option "Set tray icon to Italic until first weather update" is unchecked.