Going to new site, instead of staying open while it collects info to display the site, Firefox minimizes, then comes back when the site's ready for display. Does it rarely. But why ever?
Hello james_larrance , check it in Safe Mode, in Safe Mode window select "Start in Safe Mode" and see if this happen again, if not then see: Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems
(If the problem does not happen in Safe Mode, it is most likely because of an extension, theme or hardware acceleration).