Thanks for the report,
We'd definitely prefer fixing it than putting a warning sign !!
However, I can't reproduce the bug.
Here's what I tried, with 18.104.22.168940:
1- create a new basic effect (right-click New Asset > FX_Simple)
2- open the effect, click on the 'Create' button of the attributes panel, this creates a new 'float' attribute with min max enabled set to [0,1], and default value set to 0
3- click in the default value input box, type any value (for example, '0.5')
4- click in the value input box, type any value (for example, '0.2') OR just move the slider
And it appears to work fine. I also tried renaming the attribute before setting the values, and using the attribute in a script of the effect.
It would be very helpful if you could spot a repro-step. Are you using the attribute in the effect before setting the values? did you save the effect? does it do it always even with the most basic steps I described above?
If it appears with a speficific effect, can you please send us the effect on the support email? (support _at_ popcornfx _dot_ com)