Unfortunately, the only solution I know of is to change the URL from https:// to http://.
However, you're already very well versed and active on AE though and it wouldn't surprise me if you've already tried that and it's not working. The only real solution I could give is to play in some of the smaller worlds. I generally avoid R0/R1, and even if it's not as competitive, they seem to run smoothly with less server issues. Larger alliance route maps still time out, however, which is frustrating.
This point has been belabored to death by me and many others, but there is a really unfortunate lack of dev support for this wonderful game. Features are breaking down. I am, frankly, pretty worried that AE is probably in its last few weeks/months of operation. I kind of wonder about who still pays the bills for this website.
(If I'm being totally honest, I have been working on an AE-esque airline management game that would be browser based (would have to be scaled down a lot with much smaller worlds as cost gets in the way). I am excited to share my progress, however I obviously don't want to disrespect the developers of this amazing game by implying that I don't appreciate their work. Just that I worry about losing this game and what it offers, and I don't want to see it fully break down without anything to replace it. Airline Mogul/Enterprise just don't do it for me.)