The short answer
A browser camera page and a native RTSP viewer use different playback paths. Compare the needed protocols and local workflows rather than expecting every browser to play a raw RTSP URL.
Work through the checks
Write down the exact outcome you need: live observation, a saved event, camera movement or long-term retention. Check each outcome separately instead of treating a visible stream as proof of all functions.
Copy the RTSP path from the documentation for the exact product family. Keep the address, service port, channel and main/substream selector as separate values during diagnosis.
Use ONVIF-reported media profiles where available, and record the selected profile token. Profiles can differ in resolution, codec, audio and PTZ associations.
Check whether the selected profile actually carries audio and which audio codec it uses. Compare a known audio-capable source before treating silence as a speaker or volume problem.
What to verify
Observe CPU, GPU, memory and network use in Windows Task Manager with one view, then add views gradually. Record the point where playback begins to lag.
Sources and scope
AeoCam is available for Windows. Camera settings below describe protocol preparation, not a certification of a particular camera or a promise of every feature in every app version. Check the installed build and the Microsoft Store listing for current availability.
Vendor documents describe the camera or protocol. No physical-camera compatibility test is claimed here. Menus and capabilities can change with model and firmware.