When converting an app to 18 R5 or newer, one thing to note is that the option Edit > Attach Debugger At Startup is enabled by default.

While this feature can be useful for troubleshooting possible server-side errors, the trade-off is that performance can be hindered during normal client-side usage (E.G. loading forms, opening records, etc.).

If the app in use hasn't observed any server-side errors or the performance hit has been felt by the clients, it may be worth considering unchecking this setting to help alleviate performance.