Error 400 on first loading

I am writing a connector for Shapediver to a web site and run into a strange issue. Whenever I freshly open my page, the CommPlugin will not load and gives an error 400. Hoever, if I change the plugin version from 2.22.0 to any other version (e.g. 2.15.0) and reload, the page works and my Shapediver model loads. This also stays the case if I go back to 2.22.0. The page still works until I wait for the next day. Therefore I suspect some kind of caching issue. Can anybody help on this?

The console reads as:

POST 400

ERROR.CommPlugin.CommPlugin_1.CommPlugin.modelViewAjax : Request error: Bad request (400), Embedding not allowed Error: Request failed with status code 400
at e.exports (VM5 sdv.concat.min.js:985)
at e.exports (VM5 sdv.concat.min.js:985)
at XMLHttpRequest.l.onreadystatechange (VM5 sdv.concat.min.js:985)
logToConsole @ VM5 sdv.concat.min.js:1172
c @ VM5 sdv.concat.min.js:1836
d @ VM5 sdv.concat.min.js:1831
g @ VM5 sdv.concat.min.js:1831
(anonymous) @ VM5 sdv.concat.min.js:1831
setTimeout (async)
f @ VM5 sdv.concat.min.js:1832
m.publish @ VM5 sdv.concat.min.js:1832
log @ VM5 sdv.concat.min.js:1836
e.log @ VM5 sdv.concat.min.js:1843
error @ VM5 sdv.concat.min.js:1173
q @ VM5 sdv.concat.min.js:1219
Promise.then (async)
n @ VM5 sdv.concat.min.js:1220
r @ VM5 sdv.concat.min.js:1220
l @ VM5 sdv.concat.min.js:1211
load @ VM5 sdv.concat.min.js:1223
a.registerPlugin @ VM5 sdv.concat.min.js:1845
(anonymous) @ VM5 sdv.concat.min.js:3120
registerPluginAsync @ VM5 sdv.concat.min.js:3119
ParametricViewer$$module$build$package.ParametricViewer @ VM5 sdv.concat.min.js:3303
loadShapediverModel @ da3efb_a4f1ab332e9e9…e229f753e15.html:45
window.onmessage @ da3efb_a4f1ab332e9e9…229f753e15.html:107

ERROR.CommPlugin.CommPlugin_1.CommPlugin.initSession : Session init failed Error: Bad request at q (VM5 sdv.concat.min.js:1219)

Sounds strange indeed. Could you share a codepen or minimal html example that we can use to reproduce the issue?