Vaadin 14.0.4 IE11: syntax error in style-properties.js

We have a grid with a date-column (DatePicker).
When I use IE11 (production profile) and click into the calender-icon I get a syntax error in the console:
style-properties.js line 30.
Looks like - but this should be fixed.
In Chrome and Firefox this is working.
Any Idea whats going wrong here?

Thanks - Charly

You should create a sample project that reproduces the issue and submit a new ticket. It could be the same underlying issue that manifests now that IE11 uses polyfilled JS modules.