I added m_TimeTracker to OnStoreLoad and OnStoreSave and now the increased m_FullMaturityTime works fine.

The server doesn't save the condition of the plant between states, and after a restart the growth of the plant starts from the beginning of its current state. So if you try to greatly increase the maturity time, you run the risk of getting into an endless cycle.
Unfortunately, for now we have to settle for super-fast plants on steroids.

@Geez
Can you tell us how we could fix this issue ourselves?

@Geez
Hello. Any good news this topic?

In T186097#2699128, @Geez wrote:

WTF, why it's "Resolved" when it's not?!

If you spawn cars using the admin tools, then their endurance is ok, you can poke into obstacles for a long time. But if the car appears on map naturally, then it falls apart from a light touch, despite pristine parts and a 'green' indicator.