Thinking now it could be a combination of those two plugins AND the theme. On this dev site I have changed to a different theme, have Toolset Views active AND also the Tabby Responsive Plugins active - hidden link. I wish I could resolve the issue without switching themes. This site was working fine last week. At some point something changed and the three components stopped working together but not sure what the trigger point was.
If this is 3-way conflict involving your theme that may make it trickier to resolve (it may be that there is nothing we can do, it may or may not be on us).
Before going much further, is Bootstrap enabled on your site? Bootstrap comes with tabs, and it is just a question of outputting the markup in the required format, described in the docs: hidden link
Try copying and pasting the following into a test page and visit it on the front end to know whether it works or not:
My issue is resolved now. Thank you! My client decided to go with a different tab plugin and we were able to get that one to work without changing the theme and still using the Toolset plugins. I appreciate your perseverance.