Magento 2 Multi site cart not displaying correctly

Hi I relatively new to Magento and I am building a multi site install of Magento 2 and the cart is not displaying correctly on all  sites.

The primary domain gamedepot.uk seems to be working as it should. I can add products and it displays correctly in the mini cart and I can view the cart page correctly.

The other domains are not working correctly. I seem to be able to add products to the cart but they do not display correctly in the mini cart and I cannot select the cart page. The addition domains are gamedepot.co.uk, gamedepot.eu, technologyandmedia.uk and technologyandmedia.co.uk

I recently had cloudways migrate my site from siteground and during the process there were a number of issues in which they needed to make changes to permissions on some folders and they also created some sym links, that did not exist before. I have done some work on the site since and cannot establish when the cart stopped working as I was not focusing on checkout or the cart. I believe it was working before the move.

I am not an experienced developer and I may have done something wrong myself, 
can anyone review the sites and suggest where I might need to look. I do not know if I should be looking in Magento admin or if this is an issue in PHP or similar. I am not familiar with PHP at all. It seems to me like it might be a setting in my theme. I am using Infortis Ultimo, but I cannot work out which setting. I did do some changes to the header at a similar time to me noticing this but even after rolling back to a previous backup has not solved the problem.

I am not using the very latest build of 2.3 would my set up includes child theme. Would updating to a new build possible solve the problem?

Any help would be very appreciated. 

Michael