This BR ONLY occurs using Obsidian Mobile on iPadOS with an external mouse and keyboard
Definition to ‘Slowness to render’ means that when the caret cursor is placed (via keyboard arrow keys) in a line with markdown syntax, there is a timeout/slowness to render the source mode content of that markdown element.
In other words, it is not instant anymore when comapared to Obsidian Desktop and previous Obsidian Mobile versions.
More about this in the video below…
Steps to reproduce
● Only occurs in Live Preview.
● Only occurs when the active line has these type of content:
⦁ Markdown syntax like ## Heading, **lorem**
⦁ HTML tags like <mark>ipsum</mark>, <code>lorem</code>
⦁ Obsidian standard Callout Syntax
Open a note with the kind of content described above
Using the keyboard arrow keys, navigate to a line the has for example ## Lorem Ipsum
The content of the active line in gonna wait 2 seconds to change from ‘Lorem Ipsum’ to ## Lorem Ipsum
Switch to another line and come back to the line on step and see the result from step
Repeat these line navigation using the keyboard arrow keys and you gonna see a general slowness of rendering the content of your lines compared to the what we consider normal.
The video below shows more details about this that are hoard to describe in words.
Did you follow the troubleshooting guide? [Y/N]
YES. I did I even waited the new public and updated to iPadOS 17 before writing this BR to make sure that nothing is missed.
Tested in a New vault in restricted mode
Expected result
Instant render markdown, html and callout elements when switching the active line on Live Preview.
Actual result
Slowness to render Markdown syntax, HTML tags or Callout syntax on Active Line
Environment
Obsidian Mobile 1.4.16
iPadOS 17.0.3
SYSTEM INFO:
Operating system: ios 17.0.3 (Apple iPad)
Obsidian version: 1.4.16 (114)
API version: v1.4.16
Login status: not logged in
Live preview: on
Legacy editor: off
Base theme: dark
Community theme: none
Snippets enabled: 0
Restricted mode: on
RECOMMENDATIONS:
none
Additional information 1
This is happening in version 1.4.16
This is happening in version 1.4.8
This was NOT happening on version 1.4.2 (Canvas on Mobile).
This video is the best way to see the issue:
See video on my GIthub repository due to size issues:
Part 1:
Part2:
Source → https://github.com/FelipeRearden/videos/blob/main/README.md
See video on Obsidian Discord → https://discord.com/channels/686053708261228577/864046194195431425/1164233574212456581
The video is in a message from the Obsidian Discord because I am facing issues to upload my iPad screen record in .GIF format.
Let me know if cant see the video yet that I will try another way 
Additional information 2
It’s important to address that the issue gets worse in real life vaults with notes with a lot of content.
The performance in a sandbox is not the real life of the users that uses Obsidian since the first public release like me.
If you want I can add a video from my own Vault which show deeper the issue since it has much more content. You are gonna see that is impossible to edit a note in real life on Live Preview.
Additional information 3
Follow below the text used in the video
Focus on left note in left please which is in Live Preview
## This is a New Vault
This line has **BOLD** and an the html tag mark that <mark>HIGHLIGHTS</mark> the content in Obsidian.
The line above has a callout, lets see the issue in action
> [!NOTE] Bug Report on Obsidian Mobile
> **Lorem Ipsum** is simply dummy text of the <u>printing</u> and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.
This is not happening on Obsidian Desktop and on previous Mobile versions.
Thank you for reading this, let me know if I can help with additional tests