Hi,
Sorry for the delay in responding.
I have tracked the issue down to a plugin we use to allow pre-ordering on products. It’s called ‘WooCommerce Pre-sale, Time offer & Expiring System’ and can be found here: https://codecanyon.net/item/woocommerce-presale-time-offer-expiring-system/13335433
It’s a purchasable plugin, much like yours, so not sure how we go about getting this sorted…
I’m still within support period with that plugin as I am with this one too so not sure if you and the other developer need to solve the issue together etc.
Thanks
Gavin.