Hi Richard, Sorry from that description I can not be certain of what the likely cause is

Is this only with Firefox ? not for instance with Internet Explorer. Maybe it is a problem with how security software or the Firewall is configured.

• See Fix problems connecting to websites after updating Firefox
• And Firefox hangs or is not responding - How to fix

Have you tried Firefox's safe mode ?

• Diagnose Firefox issues using Troubleshoot Mode

Please post back to say what you have tried and if any of it helped. If you see error messages please say exactly what they are and what you were doing at the time.

It may not help this particular problem but you should remove your troublesome My Web Search plug-in. Google for information and removal advice. Do you use it? Do you know where it ccame from?

Thanks Alan, good catch.

Richard, There is an awful lot of bad advice on malware etc. removal tending to offer unnecessary, paid for or plain scam solutions. This is one solution from a reputable site malwaretips

• How to remove MyWebSearch.com redirect (Removal Guide) {Filed Under: Adware}
  https://malwaretips.com/blogs/remove-mywebsearch-com/