Mob Spawning

Please provide a screenshot of the area that show where the light sources are.

I have the exact same issue!

I'm having the same issue. Mobs are spawning in my extremely well lit base, and even within 5 blocks of my location.

While we wait for the OP to provide a screenshot, here is some information for seeing this ticket:

In previous versions of Minecraft, it was common for the cave monster cap to be filled by monsters hidden in small, inaccessible caves. The chance of this happening would increase as you spent time in an area, for example building a base or exploring and lighting the visible caves. With the new despawning system in 1.16, the hidden monsters are now able to despawn regularly, so new ones can spawn in other places. Monsters should now regularly respawn on full blocks in places you have already visited but have not fully lit.

Keep in mind that torches have a light level of 14, monsters spawn in in light level 7 and below, and spawning is based on the light level of the space just above the floor. You may find it helpful to temporarily turn off smooth lighting (in video settings) to see how the light levels change block by block.

Hi, these areas shown were lit up before the nether update and mobs never spawned, however, following the update mobs have started spawning here. 

Those areas are not well lit up. For example area with hayballs on second screenshot is completely dark. Putting glowstone on 3 high pillar lowers it's effectiveness significantly - remember that light level goes down by 1 for ever block away from source (in cardinal directions, so 2 for diagonal blocks).

Thank you Marek, I appreciate your comments but if it were true that the area is not well enough lit up then mobs still would have spawned before the update would they have not? Mobs only started spawning after the nether update in these areas which had exactly the same lighting as shown.

That is because 1.16 added mob despawn mechanism. Previously mob cap was usually filled by mobs that spawned underground or far away from player and never despawned, so no new mobs could spawn. This was finally fixed in 1.16 and now mobs can spawn properly in low light areas.

Ah I see Marek, thank you for your expertise on this. I know this isnt a technical question but could you suggest a few ways we could light up this land in a way that doesn't look ugly or where I dont have to place a light source so often

Marek is correct, and that's what I was trying to say in my previous comment. In addition, for some reason I don't know, monsters spawned by dungeon spawners count as surface, so if you had any of those underground pre-1.16 they would have blocked surface spawns. But now they do not require light to despawn.

Where you have those lanterns by the boat, the light above the ground is as follows (blue for water, yellow for sand):

Some ideas for you:

• Lower the lanterns by 1 or 2 blocks.

• Put torches, lanterns, jack-o-lanterns, etc. on the ground.

• Dig 1-block holes and put glowstone in them (I think it would coordinate well with the sand).

• Dig 1-block holes, put light sources in them, and then put carpet on top.

• Dig 2-block holes, put light sources in the bottom, then put upper slabs, upside-down stairs, glass blocks, or trapdoors on top.

• Build a 5x5 decorative fountain (like the ones found in plains villagers) and put torches on the corners, or use lanterns/glowstone/sea-lanterns for the corner blocks.

• Plant sea pickles in the water along the shore.

This ticket will be resolved as a duplicate of MCPE-302 (working as intended).