Inconsistent Wi-Fi Connection

Dear all! Would like to seek some opinion from you guys regarding Wi-Fi connection for PC. I recently moved so I've been using mobile hotspot as a source of Wi-Fi. My PC doesn't have a Wi-Fi driver in built so I recently bought a TP-Link Archer T4U Wi-Fi USB Adapter and have been connecting it to the front USB ports of the PC.

A problem I have encountered is that sometimes the PC randomly disconnects from the Wi-Fi, and sometimes even when the PC is connected to the Wi-Fi, the internet disappears/lag skyrockets for around 30 seconds - 1 minute before resuming to normal again.

Would like to know if anyone had a similar experience and any suggestions on how to deal with this? Thank you all!