@linuxgurugamer The KEI button on the stock toolbar multiplies when entering / exiting VAB / SPH / Tracking station. No other facilities cause the multiplication. KEI 1.2.6, Toolbar 1.7.16.5, Toolbar Controller 0.1.3.4 and KSP 1.3.1 with CKAN v1.24.0. No other mods were installed.
output_log.txt: https://drive.google.com/file/d/1ovVyXnO4FpxR65tuoX9HKC1Kb4jp0Vrn/view?usp=sharing
Example: https://gfycat.com/SilentEqualKangaroo
If you need more info just let me know.
Edit: I was using the KEI button on Blizzy's toolbar.