I think I have there same problem but I don't understand the answer - not unix literate!)
I have downloaded the latest astroberry and installed on a Pi3+
VAP is fine and I can connect
Tried , wlanconfig, to set up connection my home 5GHZ network. SSID and password entered correctly. Reboot VAP shows but you can't connect to it. Ethernet gets to the Pi but I can't connect to the server, it fails. Only way out seems to be a reflash.
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So, embarrassingly, it was my fault - again!! The issue was with my client - NOT the astroberry server!
I did a complete refresh again and also built a new client Ubuntu device - and it connected straight away! So I started digging and discovered the original client had some hard-wired network config in it, probably from previous testing!
So, I am going to retry the astroberry_wireless script on the original SD card, but I am pretty confident it will!!
Many thanks for your support Radek - but it seems it was my fault!!
I feel better now
I haven't had time for working with the issue recently, so it's good to hear that it was your fault
Still I need to rethink and redesign the wireless/VAP configuration. It's giving too much problems to users now. It wasn't a problem for a single band (2,4G) mode wireless available on Raspberry 3B, but dual band (2,4/5G) available on Raspberry 3B+ is quite a challenge. Of course it is not for a specific user, but ensuring it works for various users in various geographies is not that easy. 5G band is very much geography dependent due to some frequencies are used by radars. So you cannot just set a channel and it will work for everyone from Asia, through Europe to US. I will try to give it another look in my spare time.
Any feedback and suggestions more than welcomed.