Dishes

@GridironGuy88 I've had this issue as well but for me, it's not consistent.  It may be a bug or it may just be a temporary glitch.  Most recently, I just kept giving the clean up command and eventually they cleaned the dishes. Here are some things to try.

- Check for dishes on half-walls or shelves.  This may be a glitch that interrupts the cleaning. Credit: @PoptartJuniper 

- Drag and drop dishes closer to the sink.  There may be a routing issue that causes your sim to stop.
- Make sure no other sims are near the sinks.  This again may cause a routing issue.

- Right after cleanup is interrupted and your sim sets the plates down, pause the game for a few seconds. This might clear up any background processes that may be running.

- If you have more than one sim in the household, try having other sims do the cleanup.

- If the issue persists, you can drag and drop dishes in the sink.

- You can also drag and drop dishes into the trashcans but then you have to empty the trash.

I hope this helps but maybe others have different ideas.

@GridironGuy88 There are many great suggestions here! There are few additional things that come to mind for me that I didn't see listed here to consider:

• Are any of your Sims slobs or lazy? Slobs are famous for making messes plus not wanting to follow through - as implied by the title. I would also check on all traits to make sure there wasn't another type of trait that may explain any of this behavior.
• Do you have any roommates? Roommate behaviors, traits and hidden traits can cause 'trash/messy' issues. I suppose you could have a sim reacting to this or something? 
• Do you have toddlers? They are also known for leaving dishes in remote and sometimes inaccessible places (or as mentioned - shoved into a wall or something). 
• Are the dishes far from the sink? Sims can tend to 'lose interest' or motivation if they have to carry them very far.
• Sims tend to not want to carry very many dishes at once and can sometimes dump a pile after there are very many they are carrying.
• Is a ladder involved? Sims don't carry items up or down ladders unless you put it into their inventory until they have gone down the ladder then take it back out. A solution there would bt to make sure there is a sink on each floor they can access without using the ladder.
• Try to upgrade the sinks, especially in the kitchen. A sink of higher quality and easily accessible (as mentioned before) is preferred by Sims and they will head there to wash dishes sometimes. And if it's far enough away they may lose interest and dump the pile. Sigh.
• Is the dishwasher full? Sometimes they dump dishes when the dishwasher is running.
• You said you're not currently suing Mods/CC? If you did in the past and you think there may be some type of glitchy behavior going on you can try clearing out your cache:
  
  Spoiler

  How to delete cache:
  • Exit your game and Origin
  • Go to Documents > Electronic Arts > The Sims 4
  • Delete the localthumbcache.package file in your “The Sims 4” folder (your game will re-create this folder next time you open the game)

Things I tend to do to help deal with dishes on my lot:

• If you have a 'neat' Sim, they will get annoyed and will clean up most things.
• I LOVE the 'Nano Can'!!! I almost always add that as soon as I can squeeze out money for it. With a Nano Can I can drag offending dishes to the trash and 'shizam', all is forgiven! I help clean things up here and there on my lots this way - or just reduce the workload. A big bonus is that NanoCans will gradually pay for themselves since you get money back every time trash is added. (And no need to empty it to an outside trash can!!)
• I almost always get a maid. If my Sims have already cleaned the maid will just go on their way, but if there is stuff that is dirty, or dirty dishes, the maid will come and find and clean these things.
• For some households, if it fits for the type of family &/or income, I like to add a butler. They should clean these things that are left out also. 
• If you have an offending, messy roommate you can talk to them when they leave out trash to 'train' them to clean up. Sometimes they end up pitching in extra, also, once they are 'trained'.
• Sometimes I add a 2nd dishwasher for when the 1st one is running... which is frequently, since I play large households.

I hope there may be one or two things there that may also be something to consider. 🙌

@GridironGuy88 You're so welcome! I hope between all of the things to try mentioned by everyone you will find useful info. There are many creative ways to deal with these quirky Sims! I've also had times where the Sims liked one sink and/or sink area over the other and will always use the preferred one to wash dishes, hands after using the toilet, etc., even though the other sink works perfectly fine and has been live-tested. I've had the same dynamic with toilets and baths/showers. I had one huge household in a 5-story home where Sims and roomies would go up flights of stairs and past multiple, quality toilets and tub/showers to use the one I put on the top floor that contained the talking toilet and the spa day top-of-the-line tub! Even while doing the pee-pee walk of shame! Silly Sims! 🤣