pnp/sp-dev-fx-webparts Modern Script Editor Webpart page reloading issue

Question

I'm using the Modern Script Editor Webpart from pnp/sp-dev-fx-webparts GitHub. Installation and deployment all went fine and I can also execute JavaScript code on my sample modern teamsite.

Here's an example:

<script type="text/javascript">
let elem = document.querySelectorAll("[class='CanvasComponentWrapper']");
elem[0].style.maxWidth = '90%';
</script>

This code widens the canvas and it works as intended. However when I leave the homepage, going into Documents for exmaple, and navigate back to Home the script is not applied any longer. On the other hand, if I click on Home once more in the Quick Launch nav it will reload the script.

So the behavior is: After leaving and returning to the page hosting the webpart/script the script is not reapplied unless the page was reloaded twice.

Any idea why that could be?

Thanks.

However, I noticed that

Answer 1

Replace let with var to have compliant JavaScript and it should work just fine.