When you use Export As for an Artboard the granularity is 1%, i.e. if you enter 0.625 it is rounded up to 0.63. This is a massive limitation when it comes to exporting artboards and is an issue that was not in 19.1.6, where it worked fine.
There are twice as many people who care about this now! Need that decimal precision back, please. And while you're at it, can we have more characters for the "suffix" option? I don't think it used to be limited. But if you have to, how about 30ish?