Weird behavior in Gimp 2.10.14

[lonetree]

(02-14-2020, 08:12 AM)rich2005 Wrote: This is a known problem.

see: https://www.gimp-forum.net/Thread-Saul-g...in-2-10-14

and for a more hands on method, ofnuts has a plugin see: https://www.gimp-forum.net/Thread-ofn-luminosity-masks

Thank you for replying @rich2005. So I'm not the only one with this problem.

I downloaded ofn's plugin but seems a little complicated. I'm clueless now.