I have a website with GPS maps added to some Hikashop products. The products without maps can be added to the shopping cart successfully but the products with GPS maps cannot. There is no error message displayed but the product cannot be added to the cart. There is a message on Google Developer:

cart_id was not returned in addToCart AJAX call

If I switch Joomla 4 Debug mode on, then these messages appear:

Warning: Undefined array key 1 in /home/eltmsdml/public_html/dev4/KWFJ4/components/com_gpstools/layouts/default/track/stats.php on line 54

Warning: Undefined array key "" in /home/eltmsdml/public_html/dev4/KWFJ4/components/com_gpstools/layouts/default/track/stats.php on line 54

Warning: Trying to access array offset on value of type null in /home/eltmsdml/public_html/dev4/KWFJ4/components/com_gpstools/layouts/default/track/stats.php on line 54

Warning: Undefined array key 1 in /home/eltmsdml/public_html/dev4/KWFJ4/components/com_gpstools/layouts/default/track/stats.php on line 55

Warning: Undefined array key "" in /home/eltmsdml/public_html/dev4/KWFJ4/components/com_gpstools/layouts/default/track/stats.php on line 55

Warning: Trying to access array offset on value of type null in /home/eltmsdml/public_html/dev4/KWFJ4/components/com_gpstools/layouts/default/track/stats.php on line 55