Accessing Roundcube Webmail via my office connection (not PlusNet) this lunchtime - usually very fast. Going at a right crawl today. Pages taking ages to load. It's not the internet service here - other sites at working fine and Speedtest reports as follows:
Just tested before pressing "Post" and it took over 40 seconds to delete an email from viewing mode - and then returned to the inbox since the previous page hadn't fully loaded.