In such cases, our Basic XHR wrapper will be loaded afterwards, and will have to wrap these already "custom" wrapped XHR objects. This may lead to unexpected conflicts, as it is completely dependent on the previous wrapper's implementation, as opposed to the native API provided by the browser.
You have 2 possible solutions for this issue:
2. If this is not an option and the customer does not need to support older browsers, please go to Application -> Settings -> Capturing -> Async web requests and SPAs and enable Use Proxy API for XHRs. This option is available from Cluster version 1.238.