Something strange happening regarding Resolution field since recently

I notice something strange happening since recently and I'm not quite sure how this can be. We didn't really change anything in the tool. At least not that we know of that could have caused this.

When a Requester raises a ticket the Resolution field gets updated automatically as well by "System", with blank text.
In the past this was not the case and it's currently not helping out because how technicians always closed tickets is by clicking Close, then the Resolution tab would open automatically complaining that a resolution is needed. So the technician enters the resolution and selects Close as next action.

Currently when they click Close, the ticket gets closed immediately, so without giving the chance to update the Resolution tab with the correct information!
Of course the technician can think of this in advance and first manually go to the Resolution tab to enter the info and then close the ticket.
But the previous way was much much more convenient and efficient.

See also attached print screens.

Any idea what the reason can be that this changed?

Thanks