[SOLVED] pagination of category

I have categories of freestyles ,classes,weekenders. if I am listing freestyles there is no issue, if I list classes the initial page is fine and all the numbered links to pages point to the correct url (i.e. ukjive.co.uk/index.php/classes/eventslist?start=30 ) however when I go to the page it displays correctly except for the pagination links the "/classes/eventslist" is dropped leaving the links pointing to ukjive.co.uk/index.php?start=nn . I have no idea where to start looking so if someone knows where the pagination is produced please let me know (I want to try fixing it but I can't find it). Apologies for the childish scrawl, I'm trying to point out the difference between the url of the page and the url of the link.

Sorry images in wrong order.  Also version Joomla 5.3.0, JEM 4  (when I check for update it says it's the latest). "wherby" that's not a real place, my ocd just spotted a spelling mistake.
 

Hi, what is in the field JEMsettings>Global Parameters>Standard Menu item?
if this is empty I would enter there the simplelist (eventslist) menue ID. And then retry.
I am not sure, perhaps this helps.

I don't see a "Default Menuitem" in settings->global parameters

Ok now I've posted that I can't see it I can now see it I must have gone word blind, Sorry.

I see it, look red mark!
Please consult the help for that and enter the menue ID of your main eventslist!