The issue is that 1x and ADS in Battlebit are the exact same FOV, but you have different sensitivities for them, making it impossible to convert from it. The 1x should always be 100 so it's the same as ADS.
It's sort of if you want to convert from for instance a 6x scope with both sensitivity 102 AND 71 at the same time. It's impossible.
But what you can do is decide whether the 1x or the ADS is important, and just use one of them. In this case enter 100 for the 1x, and either 102 or 71 for ADS.