Hi eredwood,
Did you sort this out? I only ask because I had roughly the same problem but wasn’t able to use the occ command. I used the workaround given by Hauke Plambeck in the other thread where you posted about this : Stuck in Maintenance mode, though according to config file not - #20 by Hauke_Plambeck
I found my config.php file, changed Maintenance => true to false and the whole process revived and resolved. If Smakdab’s rxcellent solution isn’t right for you, this might be a last resort.
I had a sweaty half hour searching for solutions, so it was a big relief! I’ve come to depend on my Nextcloud server. I hope it’s all worked out for you.