Hello,

Sorry for the delay.

Please set the number of columns of the related products in the Theme Settigns > Single Product > Related products for desktop as shown: https://gyazo.com/d85c4982c5a4c3e420efbfa33b98034c

Remove all the custom CSS related to setting the number of columns, provided before.

Then create a mobile preset as shown: https://gyazo.com/07c52b34b2beb706ab7bb336b711d54d and https://gyazo.com/a8e483b7001fb6e7e6f0500ef69c0563 and https://gyazo.com/957eaa985cc0a4cdc1d5182a7ff90c1e

You need to have the recent theme version to apply presets. You can read more here: https://xtemos.com/docs/woodmart/theme-settings-presets/

If you have any questions please feel free to contact us.

Best Regards