Network error handling in excel addin is different from word and powerpoint

Question

I created an add-in for word,excel and powerpoint having common manifest. After every 30 seconds I am making a call to my server to send data. In case anytime user's internet connection turned down I give user 1 retry. SO suppose at 30th second user get network error when calling to my server, I will wait for 60th second ping also. If that ping also failed due to network connection then I show an offline screen. This behaviour works fine in word and powerpoint but not in excel (web).

In excel after I get network connection error during first server call,then excel start pinging its own endpoint https://excel.officeapps.live.com/x/_vti_bin/EwaInternalWebService.json/TestClientConnection.

I doesn't call my server after that so my retry logic will not work and can't show offline screen. Is there any better way to implement the logic I want or any way to tackle this behaviour.

I want excel to call my server instead of its own endpoint.