Does Shiny Server limit external data requests?

I've developed a Shiny app that pulls data from two different sources: one by directly parsing a JSON file with rjson and the other scraped using rvest. Later in the day, I get an "object not found" error that originates from the JSON pull (which executes first).

This error only occurs when I run the app after it's been deployed to an external Shiny Server. I've tried using the shinyapps.io hosting and my own server, but both return the same error. The app works fine when I run it directly from RStudio, but I'm really confused as to why the behavior would change when it's hosted. The only explanation I can think of is some kind of throttling on the server side, but the amount of data I'm scraping is very small.

I'd appreciate any help or advice on this topic!