SelectEx Dropdown not closing

[CaptainCannabis]

• I'm submitting a ...

  • [x ] bug report

• What is the current behavior?

The selectEx dropdown is not working as expected, The list ist always visible, options can be checked but the arrow and ticks are missing too. See image

• What is the expected behavior?

It should close on select and show an arrow in the dropdown line.

• Please tell us about your environment:

"vue": "^2.6.11"
"vue-form-generator": "^2.3.4"

• Bootstrap v3.3.7 JS + CSS

• Bootstrap-select v1.12.4 JS ( tried a newer one, but got worse result)

• Bootstrap-select v1.12.4 CSS