@missveronicatv
Thank you for your reply and is much appreciated. However we do not use a caching plugins. We do however use Jetpack and the suggeted setting for Jetpack is switched of (I actually disabled Jetpack but made no difference). Login to the site was working 1 to 2 weeks ago.
Plugins Installed are
Appointment Hour Booking, Version 1.4.30 (not activated)
Classic Editor, Version 1.6.3
Code Snippets, Version 3.5.0
Elementor, Version 3.16.4
Google Listings and Ads, Version 2.5.7
Jetpack, Version 12.6
MailPoet, Version 4.28.0
Pinterest for WooCommerce, Version 1.3.10
Search & Filter, Version 1.2.16
Ultimate Member, Version 2.6.11
Ultimate Member – Block Disposable Email Domains, Version 1.0.0
WooCommerce, Version 8.1.1
WooCommerce Payments, Version 6.4.2
Wordfence Security, Version 7.10.3
WP Rollback, Version 1.7.3
I disabled the plugins below but that made no difference:
Google Listings and Ads, Version 2.5.7
Jetpack, Version 12.6
MailPoet, Version 4.28.0
Pinterest for WooCommerce, Version 1.3.10
There are no changes to the hosting arrangement as all the other sites on my VPS that use UM are working fine.