The visualisation in the attribute table is different for fields with the same data type (some are greyed out and the values have different positions)
Any suggestions?
You can right click on the layer to open its properties and go to the Attribute Form tab.
editable
will enable/disable (and grey out) the field.
Type range
will let you "scroll" through numerical values and will right-align the number.
Type Text edit
will let your type a value and left-align it.