Since you mentioned that the adapter was working correctly and the issue started recently, you might want to check what has changed in the environment, and if possible, undo the change. Here are some questions that may help you identify possible causes:
Did you apply any change in the computer configuration, or in the router?
Were there any system updates installed?
Was any software installed recently that may be interfering with the network connection?
- Make sure that your Anti-virus database is updated and scan your PC for viruses.
If the issue persists after checking the items previously mentioned, please review and apply the recommendations provided in this thread for a similar issue:
You can apply the following actions to address the most common causes, from the perspective of the wireless adapter, for this type of behavior:
2. If the issue persists, go to Windows* Device Manager - Network Adapters, look for the Intel® Wireless Adapter and enter the adapter properties, in the Power Management tab, switch off/on the option "Allow the computer to turn off this device to save power". Check if the behavior improves when you change this setting.
3. Apply the configuration from the document: Wireless Networking — What are the Recommended Settings for 802.11n Connectivity?
4. Set your wireless power plan to Maximum Performance. This is done by going to the Windows* Power Options - Change plan settings - Advanced power settings, and set the Wireless adapter to Maximum Performance, when plugged in and on battery.