@MinKai 

Hello, the performance of RE200 is decided by the main router, we will do some troubleshooting on this unstable connection issue first. 

Please help us to provide the information below:

1. Who is your ISP?

2. What is the light status of the WR841HP when the connection drops out? Can you get internet from it via wired cable at that time? Please connect your device to the modem directly to do a comparison test as well.

Note: Please click here to check the IP address and default gateway with your devices connected to the modem/router separately and show me the status-details page. 

3. At that time, please log in to the web UI of the WR841HP and take a full screenshot of the Advanced-status page; and go to advanced-system tools-system log  to save and export it to us. 

4. Besides, please follow the instruction below to do some test and tell me which case you belong to.

https://www.tp-link.com/support/faq/2237/

Good day.