You should be able to use the optional eBay gallery images with the new templates just as you could with the prior templates. We are not aware of an issue such as you have described using the new templates.
If you look at one of your items using the eBay app, you should see the optional eBay gallery images with your image when you first bring up the listing, but to see the template you would need to tap on Seller Description to see the full description with the template you selected. Those same images and the template itself should show as usual on a full system when you check the listing at eBay.
It is unclear what may have occurred for you and we will need the specifics of what occurs and an example we can look into to assist you further with this. Please file a support case with the steps you take (in order if possible) to create a listing where this occurs and a sample of the results you describe so we can investigate what you've run into.