I tried to add a new client as a reseller after updating to 2.2.24 and that fails because it requires a title. It's impossible to not enter a title with that dropdown being present. No matter if I set that field to required or not it asks to "enter a value in the field 'title'". As I was able to add new clients yesterday before the update I think the problem must be related to the update. Updating existing clients works.
LOL, now that confuses me completely. The field above the dropdown is the company name, called "kunde_firma" in the form editor. That is filled in and is set to not required, anyway. There's no field 'title' in the form "ISP Kunde" for me.