Solution Alexa Password issue with DECO M5 The password you entered was incorrect
In the event others run into this issue...
Attempting to connect Alexa to the network after installing Deco M5 and changing the network password. If I remember, Alexa initally connected until I changed the network password and then Alexa would never connect issuing the choose another network/incorrect password. I spent countless hours trying different things and with Amazon support (which was no help). Finally I contacted TP-Link support and they suggested checking block list. I did not see the SSID Alexa uses in the list but there was a few entries (android, and Linux, etc) in the list (although not sure how they were added, I didn't do that manually). In any case, I cleared the block list and was able to connect to Alexa. I also have security set up as WPA2 only (not WPA/WPA2) and the band is 2.4 GHz only. Not sure either of those make a difference but those settings seem to work after clearing the block list. Thank You TP-LINK support!!
There's several links on the internet for this issue suggesting many different solutions and in some cases the solutions presented worked for some folks but none worked for me other than the one TP-LINK support suggested. Again, not sure how or why entries are added to the block list without human intervention but apparently it happens.