When selecting the default ancestry ability boost option for kobolds (I haven’t checked yet with other ancestries to see if this is unique to the ancestry), the options of a Dex, Cha, and Free boost, along with a Con flaw, seem to apply the boosts/flaw at 12 times, which leaves the character with a 26 Dex and Cha, and a -14 Con before selecting any other boosts at level 1.
Thanks for reporting this. It is a known issue with the builder in Firefox that we’re in the process of hunting down. 
In the meantime, feel free to test in another browser and this bug shouldn’t be an issue.