Hi, there is one possibility to getting the bad ending two after getting the "good ending" save name: if you gave away all the coin & have a low friendship with Lark (or gave some and have a VERY low friendship with Lark). I downloaded a fresh game and followed the guide exactly and I was able to get the good ending (maybe use the accessibility version to help mitigate any possible mistakes), so give it one more try. If you miss even one choice, it will likely impact the ending you get because I wrote the route guide to reduce the number of saves and replaying needed, NOT to maximize love/friendships!
Try "Don't leave any" instead of "Leave it all" but otherwise follow the guide and let me know if that works.
If you don't have any success, send me a message on Discord (natty11) and I can take a look at your save file and see what exactly is going on or provide a separate guide specifically for his good ending.