In Minecraft 1.14, unemployed villagers would claim any workstations within about 50 blocks unless they were completely enclosed in blocks.

One change I have noticed in 1.14.1 is that villagers can now only pathfind to workstations that they can stand beside. Thus, walls stop villagers from claiming workstations:

However, this causes an issue with villagers pathfinding to workstations in some cases:

• When they are enclosed in 1x1 areas
• When there is a block over their head
• When there is a block over their workstation
• When they are standing on top of the workstation

This is most common when villagers have little to no space to move around. Notice that these villagers are able to claim the workstation:

However, these villagers are unable to claim the workstation:

This can cause issues when players try to create trading halls. For example, if a villager claims a workstation but a block is placed over its workstation, the villager may be unable to pathfind to its workstation. After some testing, this only happens occasionally and only after the villager has been traded with, meaning that it becomes unable to restock. Afterwards, the villager eventually loses the workstation and is unable to reclaim it even if the block above the workstation is broken:

Furthermore, an odd bug I encountered while testing is that villagers may randomly glitch between employed and unemployed while near a workstation. I do not know the cause for this bug and was unable to replicate it on command, but I encountered it several times while testing at seemingly random times.

This villager is switching rapidly between employed and unemployed: