Click on the thread, then its call-out. Go to the hole properties and select "tapered pipe thread" and pick the right size. The only weird thing is that picking R 1/4 it seems to think the thread diameter for R 1/4 is 13.8 rather than 13.157. The G 1/4 thread is properly 13.157. That's probably why it defaults to G. But it seems to me there's a problem with the hole table in that it wants to assign 13.8 to the R 1/4 thread. As you and thread tables say, it's supposed to be 13.157. I don't know where 13.8 comes from. I tried a few sizes and the nominal ODs don't match the thread tables so I suspect a problem with SE's settings.