Hello!
There is a fix for this in Joomshaper forum... before the offical update you can do this trick:
go to 'plugins\system\helix\js\admin\layout.admin.js' on 143 no line just remove ' return false;'
Or if you are not so fond with editors just replace that file with this I put on attachment
It worked for me but not in Chrome. I tested with firefox and It worked.... better than nothing!
By the way ... DO A BACKUP COPY of the file, before you change it ... In Attachment there is also the ORIGINAL FILE.
Then clear Joomla and browser cache and have a try!