If a feature is taking longer than it should, the answer is more visibility. Pair a senior engineer. Open a WIP PR. Watch out for distractions - don't try to fix everything in one PR.
The hardest part of being a software manager is understanding that software takes the time it takes, and rushing it will slow it down and make it buggy. Patience is everything. Lots of evidence and detail here:https://t.co/YDdNJAnc12