Suggestion for SNAP function improvement after adding 'Band Maths' band

1)I opened a Sentinel-2 MSI product, and displayed it as a color image.
2) I S2 resampled it at 10m resolution
3) I ran MNDWI processor and got the result image.
4) I ran Band Maths on the S2 resampled product and imported the MNDWI image into it.
5) In the mask manager of the displayed image,I chose the f(x) icon ,but couldn’t find the imported MNDWI band—is this a bug in SNAP? I think it should be syschronized.
6) Finally I found a workaround: I save the product after adding the MNDWI band, close the displayed image and redisplayed it ,the the newly added band showed up.
Anyway ,I hope this inconvenience can be resolved in future version of SNAP.

Thanks for the report.
I just tried and it worked for me. Are you using the latest SNAP version.

Yes,I am using SNAP 9.0,the latest version.