I uninstalled Cura and removed the github clone that I had from my computer. I downloaded a fresh copy from the website. The option to check for an update did not actually work. It thought it was up to date. The github clone did not want to compile/run/install. The configuration for the download copy seems to be kind of stuck on 3mm filament instead of letting you choose the filament size. I found myself needing to duplicate the ABS filament material to make a 1.75mm ABS option. I find that absurd. Was I overlooking something simple there? Well, hopefully I can make progress on getting settled in again on the new version of Cura in case I want to use it to slice. I so often use the old copy from Octoprint for my slicing needs.
Under the Material heading do you not have the option to enter in any filament diameter you like? If the field does not show up then you can click on the gear symbol and activate showing the field for filament diameter. Or, is that where it will not let you change it?
I actually find the new Cura interface to be a little cumbersome and hard to read the settings.
@Jeff_Parish it refused to let me edit any of the existing filaments. I liked how the setup of the old Cura was for configuration. I th8nk it may have been faster at slicing too.