this is not a problem with RL Extension Manager -> I just don't know where to post this issue instead ... 😉

in joomlas own backend menu for extensions update (see picture)
the links to the modals extensions are shown as e.g. " www.regularlabs.com/cachecleaner/download "
(with "www.")
But this links are not working anymore on your new webspace -> instead the regular labs startpage appears ( regularlabs.com )

this links work only when omitting the "www.", so instead of
" www.regularlabs.com/cachecleaner/download "
it is now
" regularlabs.com/cachecleaner/download "
(only without "www." is working)