Unwanted itemset sources are selected upon click outside of dropdown

[miraage]

OS: Mac OS High Sierra 10.13.4
Championify: v2.1.5

Precondition:
+ Download ARAM item sets from LolFlavor
+ Split Up Item Sets
+ Use Shorthand for Skill Order (Q>W>E)
+ Enable Consumables
- Lock Summoner's Rift Item Sets to Map
- Don't Delete Outdated Item Sets

If we either open or close dropdown with caret, it works fine.
Otherwise, bug will occur.

Steps to reproduce:

1. Open Championify
2. Click on "Select Summoners Rift itemset sources" input => dropdown appears
3. Click on an empty place outside dropdown => dropdown is closed, first available option is selected

Screencast: http:https://take.ms/qkMvA