On my site we are using a stack to have show the header image, a search bar, and a breadcrumb in an area. This was working fine until the 8.4.4 update which caused the header image page attribute display block to not display anymore. Were there any changes to the block that requires me to change some settings to get it to work again?
Its a bit of a long shot I know but.. now that your site is running out of a new 'concrete' folder, perhaps the problem is that there were changes made to the files inside the old 'concrete' folder that were needed to display the blocks?
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