I'm not clear on what you are seeing. Maybe you can attach a screen shot.
Of course, the RMD for your inherited IRA and your own IRA are calculated separately and can't be combined
(in the way that you can combined RMDs if you own more than one IRA at different banks). Sometimes, the question is actually irrelevant. For example, in the simple situation with a single IRA that you own, the purpose of asking the question "is this your RMD" is only because there are certain things you can't do with an RMD, like roll it over into a different IRA, do a Roth conversion, or contribute it to a different IRA. (You can do these things with your IRA money but only after you withdraw the RMD and pay tax on it.) So the question is just used in combination with a rollover or contribution to make sure any rollover is valid. If you didn't make a rollover or a new IRA contribution, it doesn't really matter how you answer the RMD question.
I expect it's similar for an inherited IRA. The fact that you have both doesn't change the fact that, as long as you aren't trying to rollover the inherited IRA into your own IRA, convert to a Roth, or make a new IRA contribution, it probably doesn't matter how you answer.
