Well, this plugin is very important, because it is to follow up for push notifications. Also the problem is new, because I used this plugin for a long time. I think your renderMethod has a replacingIssue. Why you replace ' with ' and why you don't replaced all fine? Please look at =>
async='async" id="remote_sdk-js"
this should be
async='async' id='remote_sdk-js'
or
async="async" id="remote_sdk-js"
The problem is on each site (ab2go.de):