I/o Error in app while sending data in the backend

Dear OD Users,
We have an app we have 2 huge tables where 1st table has almost 1 Million rows & 23 columns and 2nd table has 1.5 million rows & 23 columns. In the app, there are 2 tabs, and each tab uses one of these tables. So, when a user switches these tabs while loading the data then the app throws an I/O error occurred while sending it to the backend in the console, and dataTable could not be loaded.

Any suggestions or ideas regarding this error?