Why is Oe in the SI list? The modern developed unit is H in A/m.
A/m is not ONE unit but a combination of two. So you won't find it in the unit list. You also won't find m/s when you look for speed units, but any speed will be automatically shown in m/s.
You can always type in A/m yourself as you like.
And results are displayed in A/m anyway. So I can't spot any problem.
According to Merriam-Webster:
Oeersted: the unit of magnetic field strength in the centimeter-gram-second system. First used in 1930.
According to Wikipedia (that you need to check):
The original motivation for the development of the SI was the diversity of units that had sprung up within the centimetre–gram–second (CGS) systems (specifically the inconsistency between the systems of electrostatic units and electromagnetic units) and the lack of coordination between the various disciplines that used them. The General Conference on Weights and Measures (French: Conférence générale des poids et mesures – CGPM), which was established by the Metre Convention of 1875, brought together many international organisations to establish the definitions and standards of a new system and to standardise the rules for writing and presenting measurements. The system was published in 1960 as a result of an initiative that began in 1948, so it is based on the metre–kilogram–second system of units (MKS) rather than any variant of the CGS.
So you are technically correct, Oersted is not SI. Prime 4.0 Express with CGS unit specified. (Built-in unit not specified?:
With MKS specified
And with USCS specified:
So Prime has issues with units.