Hello Paul and thank you for your enquiry.
Some of the settings you mentioned are meant for the usage of some integrations.
I will personally go deeper and be back with further informations.
More explanation @Paul:
When the issue occurs, should see if restarting presence or lookup helps. If so - that is the issue and should be sorted. First need to ensure that that is the issue...
Hello!
You can mark it as closed as option. If document is connected with other documents you can not delete it so you will not be able to delete PO, as you will not be able to remove Goods receipt...