As a workaround would you mind testing your survey form by doing as suggested below:
Make a backup of your survey project (xlsform) so that it does not get distorted with the workaround.
Remove the complex syntax that is with your xlsform and see if you are able to upload your xlsform. Here if you are able to upload your xlsform the issue should be with the complex syntax and not the number of questions that is within the survey form.
If you still have an issue uploading your xlsform despite the fact that you have removed the complex syntax try removing some question and see if you are able to upload them. As far as i am concerned the number of questions should not affect the deployment of your survey form. It should only affect the loading of your survey form once they are deployed.
Thanks for your response. There are some complex syntax related to relevant. It is a part of our survey, so it is not ideal to be removed. Please have a look at the XLSForm. Testing DSA_20200705.xlsx (385.8 KB)
Kindly get back if you know what might be other errors.
Thanks for taking a look at the form and suggestion. I tried splitting the form by sections and deploy it. It works just fine. And the image you have sent, that might not be from my form since I did not have that syntax (I also searched my form again to clarify and there was no such syntax).
The issue was still there. However, I changed the format of the survey and delete many matrix questions. Number of questions has been reduced significantly so it is working fine now, although it is still slow considering many skipping logic and constraints.