I wouldn't have tested it, but yeah it does nothing in my case. My was set to default, and if I change it... looks the same.
LOL, same here. All I know is @teslasystems would have a bright future in software QA...
It's very strange. I've noticed that these modes do work on 'All categories' page, but they don't work in this topic...
Today's "maintenance" was ... unsuccessful.
maybe that was the maintenance about: y'all be having too many options
The latest changes also hide who upvoted/liked a topic. What is the purpose of this?
I see my avatar attached to thumbs-up on your post, and I can parse credit for another up-thread.
All I get when hovering over a thumbs up (including yours) is the spinning wheel. This is what recently changed.
What did not change: For Hearts it does display user. For thumbs down it does display user. I am using Chrome Version 148.0.7778.168 (Official Build) (64-bit) on Win 10 Pro
Note that the tangent that is displaying is because the gray box is not opaque, and if it your name from the next post.
Another example:
Here are the ones that still display:
hovering over heart
and hovering over thumbs down
Can confirm that.
Regarding modes, they don't work, because sometimes there is no appropriate class in <body> tag.
For example, on 'All categories' page the class exists and specifies 'Cozy' mode:
But when I go to this 'Migration ...' topic, there is no any class that specifies current mode:
This causes page size changes. Left sidebar becomes larger and smaller while browsing between different forum pages. Very stupid and annoying.
UPD: and what's interesting is that when I open this topic, there is no class in <body>, but if I jump to the very beginning using timeline, it ... appears 
Are you gonna fix what you've broken?
Theme component Density toggle will be disabled for now. It seems that it might have a bug or is not fully compatible with current discourse release. Also noticed that Discourse them selves have disabled it on their meta community site.
And what about the other issues mentioned above?
Selection mouse over shadow was recently fixed in updated theme version. But it seems that we missed that likes/dislikes double popup.
This is not good. Personally I switched it frequently depending on conditions. I used Default mode when sitting far from a screen (4K, 150 % zoom), Cozy when sitting closer and Compact on a laptop via RDP (1600x900 100 % zoom) . Now everything is too large.
Please, return it. Even a buggy behavior is better than nothing.
Could you clarify, what issue are you talking about? The problem with likes is that it doesn't display users who left "Thumb up" to a post and infinitely "loads" it.
Please give us compact mode back, please .... not all use phones or tablets to browse forum.
Might be and issue with our logo image format and IOS app related specifics. We'll check on that.
I'll recheck info on Density toggle plugin/issue in discourse community, but if they are thinking of abandoning the plugin wont or not fixing the issue it wont be re-enabled. Keeping outdated/abandoned plugins enabled, per my experience just leads to issues with systems in long term.
Regarding Reactions plugin. It might be an bug. I will need to check with newer build in test env and see if it still presents it self there.
In case it won't be reenabled, are there any similar plugins/extensions?
Any update on this? It is a bug. What's odd is that when I access from an android device, I can see at least an Icon for the thumbs up. From windows, just get spinning wheel as demonstrated by @teslasystems in this post
For now, when the spinning wheel appears, you can click on the thumb up icon once, and the list of users will load.
Currently, on hover, this GET request is triggered (example URL https://forum.mikrotik.com/discourse-reactions/posts/1149703/reactions-users.json?reaction_value=+1):
But it returns only an empty array:
When we then click on the icon, a second GET request is made, this time without the reaction_value=+1 parameter (example URL https://forum.mikrotik.com/discourse-reactions/posts/1149703/reactions-users.json):
And the request returns the user list:
Which means maybe the plug-in needs to be edited to remove the extra parameter in the URL.
Here is the JS code responsible in discourse-reactions-custom-reaction.js:
Ok, it just a missing URL encode problem. reaction_value=-1 and reaction_value=heart work normally. But reaction_value=+1 of course does not work because the + character in URL parameter is normally translated into a whitespace. With proper URL encoding + -> %2B it works:
Example: https://forum.mikrotik.com/discourse-reactions/posts/1149703/reactions-users.json?reaction_value=%2B1
In the reaction plug-in JS code above, options.reactionValue should be wrapped by an encodeURIComponent() call: encodeURIComponent() - JavaScript | MDN.
Thanks @CGGXANNX. Your workaround of clicking on the thumbs up while spinning does work.