https://allstarlink.github.io/ I would start here. I too went from hamvoip to ASL 3 and not one single issue. Well at first I had one but it was operator error. ASL 3 is fairly simple to setup. First thing I would try is to see if you can access your node via terminal or putty. If you can then log in and do a asl-menu. Run through the setup and see what that does. Nine times out of ten its not configured correctly. Cant blame the software when it works for twelve thousand other people!
I feel there is a warning that should be posted in LARGE BOLD print in the manual.
On first boot, WAIT, WAIT, WAIT and least 30 - 45 minutes before you attempt access or you will screw up the installation!!! This sounds like your issue exactly. It's happened to me and I've made many ASL 3 installs on Rpi's with the pi-appliance.
I like Hamvoip and went thru the same things you are running into… not fun, BUT ASL3 is better because of its security. (but not really the passwords.) But you can find and change every password in ASL3 except the pi login made by Pi-imager….
There is no account created named 'pi' in the ASL3 image. Only the account you configure during the flashing of the card. And that's trivially changed with the passwd command or within Cockpit.
It's unlikely you need to wait "30-45 minutes" unless you have something horribly slow like a Pi Zero 2W or are connected at dialup speeds and you imaged from a old build. There are 3 reboots max of the image- one that resizes the root partition, one that does some other "firstboot" things including a package update, and then the final one after the updates. If you're seeing it take 30 minutes, I'd be curious to know what image base you're using, what Pi it is, and what the monitor is reporting while it's taking that long. Something isn't right there.
Latest RPi image, RPi 4 w/ 4GB RAM, 32 GB SD card, 100 mb wired network. It was just about 30 minutes before the activity completely stopped. Total time including configuration was just under an hour.
I have been bit too many times by waiting for the activity to appear to be done and getting hosed. Now I just WAIT, WAIT, WAIT at least 30 minutes and now I have no problems.
I was installing on to a rpi zero 2w. no, i did not wait 30 some minutes. retried everything a day later and everything fell into place. The learning curve compared to hamvoip was rather steep for me. Now that I am more familiar with what to expect, I should be able to move on from here. A lot of what I had issues with could of been related to processes not completed before moving on to the next.