Note: This is actually on 20w20b.  

I went to harvest bee nests at night and while it was raining.  I was using an iron silk touch axe (Eff 5, Unb 3, ST) and was able to harvest three nests.

No bees were visible around any of the nests when harvested; although it was night and raining when I harvested all three.  All nests were full of honey prior to being harvested.

I saved my game and returned to it later.  Meanwhile, the bee nests were in a chest in my base.

Later, I placed the bee nests above upward-facing dispensers.  The nests were still full of honey.  The new location of the nests is a glass and stone enclosure with dirt and flowers.  I activated the dispensers using glass bottles and was able to retrieve a bottle of honey from each nest.

Now, a few in-game days have passed and no bees have emerged from any of the three nests.  Could this be:

• because I saved my game prior to placement? 
• because I left the bee nests in the chest too long?
• due to my mod loader?  I'm using fabric-loader-0.8.3+build.196-20w20b.  This is a single-player local game (Integrated server).

What I expected to happen

Bees should have been in the nest at night when raining, and should have re-emerged after placement in the new location.