not working unless 4 additional characters...

We have an accordion working well with an events booking site module see Upcoming Activities: diamondvalleybwc.org.au . The site module allows pre and post text where we have made the pre text {accordion title="Upcoming Activities - Tap to View" open="false"} and the post text is {/accordions}. It works as expected.
If we change the pre text to {tab title="Upcoming ..} and post text to {/tabs}, the tab is not recognised unless we add at least 4 characters before or after e.g. {/tabs} ABCD. If we change {/tabs} to {/accordions} the tab works.

When the tab fails, the site module displays:
{tab title="Upcoming Activities - Tap to View" open="false"}
The upcoming activities
The post text {/tabs} does not appear.

We have the latest version of tabs and accordions (Pro) and are on Joomla 5.2.5.
Hope you can help.
Best wishes,
Noel Adams.

Hi Peter,
I have updated the site module so it should produce a tab. You can see it does not.
Thank you,
Noel.

Hi Peter,
Thankyou for your reply. It does appear to be an issue with the site module. I changed Closing Tag(Tabs) from tabs to tabulations, and with the longer closing tag the tab now works. I will ask the event booking developer for support to fix. Thank you again for your help.
Best wishes,
Noel.