On Staurogyne and some other plants. The general guide Tropica has is right.
But there are plants which easier to melt in new condition than others.
Maybe this is something what would be nice to have highlighted in a catalog since we know many of them.
But if not then your retailer need to inform you which are the typical problems.
I usually try to avoid selling plants which is 50-50% success rate to stay alive to any beginner. And tells to my clients to go with an easier one.
They seen a perfect Utricularia carpet? Nice, keep that in mind coz 99% that you will not have it
Do it when you're ready to play a little and accept failures.
Crypts, Blyxa, Staurogyne melting? Well they look bad after that but hey most of them grows out quickly from the roots again. And that plant will work better with your water condition then.
Just give it a little time. Maybe you will not have a beauty Staurogyne bushy part in 2 weeks but after 4 months you will hate it how it's overgrown and need to take care all the time
Patience. That is the key. I only have a few plants in my head which i do not like to work with. All others works immediately or after a little time.
We do have 20 display tanks. And i frequently sees that if i move over a wonderful microsorum trident bunch to another tank which also running with the same RO water, same temp, but the micros will have algae on it after a week.
Stress, just a little conditional change. Coz in the other tank has a decoration element which raise the hardness a bit. Light, CO2, ferts everything else is the same. And still it will be a harder 1 months to get over on this thing.
Same with Riccardia moss and many others. This is normal.
If we accept that these are living things and need time to work with the new environment we will see more success stories.