macrogy The akeeba backup file size is too large around 1.4 GB henceforth, getting interrupted and not being completed while downloading the same. Probably, You can decrease the akeeba backup size by excluding large files which dont hold much relevance in here in troubleshooting which would faciliate download with ease
Also, While enabling enabling debug system --> enabled from the Joomla! Global Configuration, System tab, by setting the Debug System option to "Yes" , Following error can be seen as seen in screenshot for which solution had been suggested here for the specific error however specific code snippet isnt there in index.php file of JB Ascent template due to which unable to figure out the precise issue
Have reported this with JA Dev. Team and will revert back as we get an update on the same
Thanks for your patience