This also happened to me. I was mining stone blocks on the surface with plenty of room in my inventory and the blocks would not be picked up as I moved through them. They just remained hanging in the air. The was with 12.3 on an iPad Air.
No mods.
I should have said that this refers to birch planks and not birch wood.
I don't think this issue is related to the one that you reference. I did mine a lot of birch wood but I would not have converted the wood to planks in such high numbers. Only converting it when specifically needed.
I added an issue that all nether portals in the Overworld lead to the same portal in the nether. Having played the PC version, this should not work this way.
I received a response from Mojang that this had been fixed and the issue was close.
I made a creative world in 0.13 on my iPad Air with two portals in the Overworld separated by a large distance. Same result. Both portals led to the same portal in the nether.
Mojang, please fix this so that it is the same as with the PC version.
I did do a search but could not find a similar report. Anyway, if this is reported as resolved, why am I having the problem?