If you want people to give up their time helping you, the least you could do would be to give up your time to rule out other possible causes…
Anyhow, MultiSafepayDev I’m really not sure your gateways are coded correctly. For example in WC_MULTISAFEPAY_Banktransfer and the main file:
1. It uses notifyurl which is not part of this gateway. Is the main ‘plugin’ is not installed this will fail. it’s installed as a separate plugin but cannot work standalone.
2. It tries to trigger new order emails manually (?)
3. Deprecated use of add error functions
4. Un-necessary use of $woocommerce global
5. update_status calls are updating to wc- prefixed statuses which is not necessary.
6. Notices in use (see earlier in this thread)
I wonder if you’re receiving stock emails? I do with other gateways. it’s handled correctly in core.