I work in this small team where my "manager" has been the solo backend developer for 4 years.
The person before me left after 9 months.
When I joined the team I immediately noticed that the solo dev was jealous of the project: was not able to share the right information with me, and often he simply didn't share the information, he kept the most important task for himself, and when he must review my code he wait for ages before doing it. Nothing is deployed without his permission, and more than once he waited MONTHS for a code review on my code, with the consequent flood of conflict to resolve on my side. He complained about other teams, about other people, about everything, but when we were in front of our manager's manager, he became a little lamb.
I asked help from the product owner and the manager director, but nothing happened, they just shrugged. moreover, my "manager" took over my tasks after 8 months without any communication.
WTF is this behavior??? Does it happen to someone else?? How to deal with an environment like that?