This problem began with the latest update to InDesign.
I duplicate a page with a table. The page is identical, except on the new page the tables have the headers removed. The headers return by inserting a new row > Header and new row appear > then I delete the extra row. So there is a way to get around the issue and it's not critical, just annoying.
InDesign 2017.1, Windows 10 Pro
This issue is known but still I request you to report it as a bug at Feature Request/Bug Report Form
As a workaround you can try any of the following:
These should work for you. Hope these workarounds would be less annoying.
A fix for the issue reported by you is available at https://helpx.adobe.com/indesign/kb/troubleshoot-issues-indesign-cc-2017_1.html Please follow the steps mentioned in the link above and install the fix.
Also, note that fix is only for InDesign CC 2017.1 application.
Kindly, share your feedback.