MKR1010 laggy when connect to wifi that doesn't have internet

Hello, I'm using an MKR1010 board for a project at my company. It functioned well for four months. However, today we have an internet issue at the office. The WiFi is running but there's no internet access. When I checked the serial monitor, I noticed that the board's loop function is running significantly slower than usual. Interestingly, if I switch the WiFi to a nonexistent network, the board operates normally again. I suspect that being connected to a WiFi network without internet access is causing delays in the loop function execution. When it tries to connect to a non-existent network, it doesn't face the same issue. Has anyone else experienced this problem? Any suggestions on how to resolve this would be greatly appreciated. Thank you!