We cannot see the metrics you are using here. Please consider that eVars can persist even after the hit/server call that sent the specific value. Check the eVar expirationCheck the eVar allocationIs the metric a global once like visits or a custom one that needs to be physically sent?  

Could you let us know what is the exact application. Does it has a web view as you mentioned a client?    If not the main issue would be to track the unique visitors via data insertion API. I have done an implementation once that did not involve a web view so it was all server side and I initially f...

This issue does not seem to be linked to any adobe products. You should contact youtube support 

Remember that pageName would be truncated to 100char to dynamic variables or processing rules will most likely limit to 100 char during processing in your eVar as well.   We use an eVar for pageName and we just reuse same adobe launch data element for both s.pageName and s.eVarX

Please provide URL where you have the issue and we can have a look. Not much to go on here for us to be able to help.

I believe Adobe I/O does not use Single Sign On so if your company uses SSO you might be using different accounts as the one you would use on Adobe I/O would be your Adobe ID where in SSO it would be the Enterprise ID even if you are using same email. 

Check this: https://developer.adobe.com/analytics-apis/docs/2.0/guides/ as it goes over permission. I would have expected Adobe I/O to show you all services available in the company when creating a project and if permissions are not correct they would have failed during runtime.   Are you sure you a...

Perfect answer.   Events are only allocated to an eVar is it is sent in the same server call as the event or is being persisted.   Order ID should ever be generated when the purchase is completed and should never exist during checkout process or cart process, therefore it is normal that any events t...

Check hit_source in your data source to understand where the hit is coming from. Also check exclude_hit to make sure the hit is not exlucded.   Just by what you described I would guess the hits with visit_page_num=0 would be stitched data from target using A4T integration so that would make sense th...

2k rules is way to excessive.   Before doing any work I would start by doing an audit and doing a refactor.