A hotspot that disconnects after you stop using it is not necessarily broken. Apple's iPhone guide says devices disconnect when the hotspot is unused to save battery. That explains an idle gap, but not every interruption during an active transfer.
Describe the moment it stops
Suppose you close the laptop for lunch and return to find it offline. Compare that with a connection dropping repeatedly while you read a page. Record which situation you have before changing settings.
On the iPhone, check that mobile data works and open Personal Hotspot settings. Confirm the intended sharing option, then reconnect from the laptop's Wi-Fi list using the expected phone name. Stay on the settings screen during the initial connection as Apple's troubleshooting guidance recommends.
Keep two problems separate
- Can the laptop discover and join the hotspot?
- Once joined, can the iPhone itself reach the internet through mobile data?
If the first works but the second fails, repeatedly changing the hotspot password is unlikely to answer the right question. Check the mobile connection and your operator's support for tethering instead.
Do not promise yourself an always-on replacement for a home connection. Availability depends on the operator, plan and device setup. Save important work locally before a pause, and verify that an interrupted upload completed rather than assuming reconnection finished it.