I have been using MariaDB for the past three years as a spatial database with no issues. Suddenly on the update 10.3.29 where they introduced new spatial feature, it caused spatial index not to work properly. This means any searches by using bbox were not working. The bug was reported and fixed for the next release. The next release will be after three months.
I managed to overcome the issue by sacrificing performance until the release is available. What I can not get my head around is what would happen if I did not found a temporary solution until the next release?
Is this something that is expected when you are working with open source?
Do you have a duplicated servers with different versions of MariaDB?
How do you protect your self/server?
P.S. Downgrading is not an option/supported
To try to answer the question, usually that's the reason people wait for stable releases.
Stable releases are not cutting edge, but it is usually pretty stable.
You should apply only security updates in the meantime.
Upgrades should be planned, tested before hand in virtual environments for example, and applied in a controlled fashion to the production environment, same as with proprietary technologies.
As for open source vs proprietary software, both sometimes have bugs occasionally. But you can help alleviate that risk by using stable open-source versions/distributions.