[2260] Internet Explorer 11 issue - Object.assign polyfill gets resetted

Hi all, has anyone else expierneced the following weird issue with iexplorer 11? I always run into "Object.assign" is not a function errors.. even though it actually is polyfilled. At least during the beginning, somehow (magically?) it gets resetted to undefined after the final page load. So if i output "Object.assign" during page load, it has a function in it, but if I try it to use it later one (by anothr functino or just by typing it in the console) it tells me that object.assign is not defined anymore.

I get errors like:

Das Objekt unterstützt die Eigenschaft oder Methode "assign" nicht
./node_modules/vue-js-modal/dist/ssr.index.js in t.default.methods.genEventObject at line 469:0
./node_modules/vue/dist/vue.runtime.esm.js in n at line 185:0

I polyfilled it with my own class, with predefined polyfillers and so on.. no change. I even tried to "re-polyfill" it after a while and after the final page load.. but without success. I will appriciate any clue or hint from this awesome nuxt community!! Thanks guys