Why does my Pixel 9a lose Wi-Fi after inactivity?

I've recently switched from a Pixel 7a to a 9a due to a broken screen. On the Pixel 9a, I have a very strange issue: When my phone is inactive for a while, it keeps Wi-Fi connection (icon on the top shows Wi-Fi), but when I try to open the browser and do anything, it hangs as if I have no internet connection. On the Wi-Fi page, it also says "Connected / No Internet". Other devices on the same Wi-Fi connection have no issue. To resolve the issue, I have to turn Wi-Fi off and back on. Then it works normally. Why does this happen? How can I prevent it? My Pixel 7a didn't have this issue. Here are some things I've tried, that did not help: - **Disable Adaptive Connectivity** -- It seemed like the most likely suspect, plus it was recommended on some reddit thread. Didn't work. - **Disable VHT80** -- It was recommended to me to disable VHT80 on my access point and switch to WHT40 or just Full 20. I tried that, didn't make a difference. - **Switch to WPA-2** -- It was recommended to me to disable WPA-3 and switch to WPA-2. I tried that, didn't work. - **Reset the Network Settings** -- As suggested by Robert in the comments, I tried resetting the network settings. That did not fix the issue. - **Disable Adaptive Battery.** -- As suggested by Rohit Gupta in an answer below. No change. - **Disable Private DNS** -- Suggested by Gemini AI. Seemed hopeful at first, but did not work. - **Get a replacement phone** -- I contacted Google, explained the issue, and was offered a replacement phone. New phone arrived, different IMEI number, but still same issue. - **Delete the DuckDuckGo app.** -- This was the only app I installed pretty much after a clean reset, when asked which search provider I wanted. It also installed some kind of VPN service unbeknownst to me. It *did* drastically improve response times to pings, but the main issue still persists. - **Disable DHCP** -- I tried disabling DHCP, enabling a static IP address, as I read Android had some DHCP-related bug at some point. No change. - **Set 8.8.8.8 as DNS** -- Might as well try. No change. - **Use 2.4 GHz Wi-Fi instead of 5 GHz.** -- Perhaps that had some effect? It did not. I'm running Android 15, build BD4A.250505.003. My router is a Linksys WRT1900ACS. # Update: I reinstalled Android from scratch, and now the Wi-Fi connection is even worse. It randomly breaks, even when the phone is actively in use. I've tried pinging the phone continuously while it's in use, and I get

From 192.168.1.3 icmp_seq=10 Destination Host Unreachable

repeatedly. At this point, I genuinely believe that my phone's hardware is broken. # Update 2 I received a replacement phone with the exact same problem. Maybe the idea of having internet in my own home is just too complicated for modern tech.