When in a swamp or a slime chunk, I observe a slime and create a simple farm with appropriate lighting, Y-coordinate, and conditions according to the Minecraft.Wiki website. I have built these farms (iron golem + cactus) before, prior to this update without problems. However, slimes cease spawning in either the chunk or the swamp after I start digging out the area. In the case of the swamp, I have several AFK spots to just observe what happens in the swamp - no farms or lighting. Slimes do not spawn. I have observed from varying Y-coordinates as well but there does not seem to be any distance from the player at which a slimes will spawn.  

My husband and I both experience this issue on our separate platforms and devices. We play on Realms but this issue persists if I create a Realm download (both on normal and hard difficulties). My husband plays on Windows 10 PC, Minecraft v. 1.14.4 and I play on iPad, Minecraft v. 1.12.0. 

We have tested and observed this issue for one week and we play for about 4-5 hours every day after work...In my case, this amounts to at least 20 hours of testing and observing various environments, Y-coordinates, farms and lack of farms, locations, etc. I should stress that this issue persists even when there is no golem or lighting and the only factor I can control which would affect slime generation is the distance between myself and the slimes.

*This may be a duplicate of MCPE-48950 which contains two bugs in one ticket.