Look at the dates on the posts in this topic. Personally, I had problems before 2.0.5.1_beta_2020-01-18. but debug/fix efforts prevailed on many of them. There are some unfixed, maybe due to the developer shortage. Others are rare, and poorly understood because they’re rare. Reproducible test cases can help immensely.
Good practices for well-maintained backups has things you can do to attempt to keep things happy and fast.
For a sense of scale, https://usage-reporter.duplicati.com/ shows 4 million backups/month. Not all post. 
Keep multiple backups of critical data, maybe by different programs. Reliability varies but none are perfect.
If you’d consider a licensed closed source GUI on top of an open source engine, some folks like Duplicacy. Comparisons are hard due to different user base sizes and uses, so personal evaluations become helpful.