the signal intensity problem when i test the example of SoftAP

[luiqwer]

The board i used is ESP-WROOM-32 ,after I downloaded the example of SoftAP，i use wirelessmon to monitor the wifi signal intensity when i connect my device，the result is shown in the figure.

10:15:48 i start wifi
10:19:33 i connect my phone
10:22:03 i connect my computer

what problem me is why the signal intensity is not stable when it have no device connected，and it seems that different device may effect the signal intensity . when i have the computer connected, the wifi signal intensity can be stable.

I can't confirm if it's a hardware or software issue，because another board ESP32-WROVER-IE also reproduced this phenomenon.

Hope someone can help me,
Thanks.