Deco M9 Plus inconsistent speed after firmware update to 1.5.0
I saw that there was an US firmware update avaliable on the site, and I decide to update my Deco from 1.4.3 Build 20200921 Rel. 42500 to 1.5.0 Build 20201211 Rel. 42330 following the PDF instruction. After updating using the update program, my app shown that the version was still 1.4.3 Build 20200921 Rel. 42500. This was odd, so I use https://tplinkdeco.net/ to check, and saw that only the main Deco was not updated. So I did a local update using the site, and it update all three. But now after all 3 Deco was update to 1.5.0, I see that my speed is inconsident. Before, I was consistently getting about 311mbps/11mbps wired. But my last 3 ran SpeedTest gave me 176mbps, 314mbps, and 78mbps. Also whenver I use https://tplinkdeco.net/, it keeps giving me a Operation failed message, and does not show my WIFI information. I haven't touch the any of the app settings.
Is there a problem with this firmware?