xsengine returns the javascript source code instead of results of operation

Hi Experts

We are on Rev 66 on AWS.

We have run into this problem multiple times. Every now and then, a request such as

http://host:8000/xsjs/p1.xsjs?qp=value

returns the p1.xsjs file verbatim instead of executing it on the xsengine and returning the outcome.

While this is going on, most other requests to the same p1.xsjs work just fine. With browser F12, I can see the headers returned when it works:

Cache-Control    no-cache

Content-Length    2341

Content-Type    application/json; charset=utf-8

Expires    0

Proxy-Connection    Keep-alive

Set-Cookie    xsSessionId=5D038498A25C3B46BE94F7C9A287DEB6; path=/xsjs; HttpOnly sapxslb=3F4805FA11E3C9468DE89EA410E2C7AA; path=/xsjs; HttpOnly

It also exposes the server side source code :-(

We end up restarting HANA, adding a blank line to the xsjs code and reactivating it. Sometimes it corrects itself after some time. There is nothing in dev_webdisp or dev_icm_sec trace files a the time of these errors.

I will appreciate your help in discovering and plugging whatever is causing this.

Thanks a lot.

Dinesh