Just spent a lot of time trouble-shooting older linked-list blocks. The links break if conditional filters look like this:
Rather than this:
May want to check and re-configure them, if you have older linked lists.
Hi Ben, If you see such thing, it mostly means that you have changed the list details datasource table/sheet or reordered the block by adding another list details block on top of the page with a different connection, which is why the linked list conditional filter got disconnected.
Please, follow the instructions mentioned in this help doc
Hi Maria. The old conditional filter setting (i.e. 1st circled screenshot) was working until recently. When I noticed this, I did not change the datasource or table settings, or blocks. The only changes made were the conditional filters. When I re-configured the old filter setting, to the new one (2nd circled screenshot), they linked correctly again. All I did was remove the old filter and set a new filter to the same setting and it worked 
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