Hello,
Please make sure that the WooCommerce my account shortcode is set correctly in the edit page:
[woocommerce_my_account]
Then, go to WooCommerce > Settings > Advanced, then click Save Changes to set the My Account page in the section of Page Setup.
Please read more here https://woocommerce.com/document/woocommerce-pages/
If you have any questions, feel free to contact us.
Best Regards,