1/ “I have tried exporting the .DAT file from parent to child theme but the child theme still does not work.” – Are you referring to the API not working, or the appearance of the website? – I was refering to the API not working, the appearance is fine with either theme.
2/ Have you entered any API keys in the WordPress admin area (possibly in the plugin settings), as they may change depending on the active theme? – The API keys are set from Woocommmerce in API-rest and entered into the third party software (Linnworks). I can try re-registering the API keys in Linnworks once the child theme is active and see if that works.
Please let me know if you have any other suggestions.
Thnaks