Hello @ikmo7 We have reported this issue and then Adobe have documented the limitation, there are few approaches you need to adopt based on your business requirement and how quick you need this click attribution.
Let me chime and detail out few nuances which might help your situation.
#1 Increasing the limit from 15 days: Reach out to Adobe support or TAM and request to extend this, at this point of time the max expire can opted is 30 days, there is also an enhancement submitted to provision this as configurable variable in UI in future.
#2 Adobe AJO wraps url's differently for each channel based on your message settings and coding.
Email: Consumer URL's will be wrapped with subdomain starts with "data." for emails opens and click tracking in real time.
SMS: With SMS links might be wrapped multiple times based on implementation.
1) with AJO shortening service, links we be wrapped twice once for click tracking (you can observer this network traffic) and other for url shortening to circumvent vendor character size limitations.
2) without AJO shortening service, links we be wrapped only once and this would eat up your vendor character length due to product construction of url.
#3 Offloading URL shortening to external service for SMS and suppression AJO tracking & shortening services will not provide the real time click attribution, furthermore these shortening platforms does differentiate individuals(profiles in our CDP world) in order to load these interactions into platform for further consumption.
Let me know if you need more details on this.
~cheers,
NN.