I've noticed similar issues with plain text files or files similar... mostly on txt files, but sometimes on others and I have been trying to find a reason...
One I can think of is a possible memory leak because it typically happens on non text files more and more the longer I leave the window open but can occur immediately after opening if a lot of other things are being worked on...
Now, for me - when I type, and I type incredibly fast, it appears as though the window has locked up.. or at least the UI thread.. I can't do anything.. But, I can type incredibly long paragraphs and 100% of my text appears after a few minutes ( yeah, minutes at times )... If I click away from the window and back, then not 100% will show up - I'll lose some text...
So - when this locks up for you, if your cursor is in the window - try typing something and wait a few minutes to see if the window unlocks and the text appears... if this is the case then it is likely the ui thread locking up or being locked by some task ( maybe a non-async called function called by a plugin - I tried setting my plugin to use a non-async function and it caused a lock up for about 10 seconds but when in async mode the data appears immediately... so the ui thread is very prone to lockups and if something is causing it we'll need to find it and let the mod author know...
hopefully there is a common thread we can find to help isolate the issue...
What does your console say?
What are all of the packages you have installed?
Are your packages extracted or not?
What OS are you running?
Console doesn't seem to show anything..
I have a lot of packages installed and a lot are extracted but I have been going through and deleting the extracted ones in favor of the packaged ones... I'll list them below..
Windows 10 Pro x64 on a 10 year old 2.4 ghz quad ( at 3.0 on air ) with 4 total threads - no hyper threading.. 8gb ddr2, and 8gb ddr5 with 1080 gt, and 2gb ddr4 with 750 ti... 4 to 6 monitors depending on what I'm doing..
These are the ignored packages:
"Github Color Theme",
"Highlight Trailing Whitespace",
"Line Endings Unify",
"Nightwalker Color Scheme",
"Project PHP ClassBrowser",
And when I choose disable package - these are the ones that show up:
_Acecool - Dev folder where I test theories outside of standard packages - currently empty
AcecoolCodeMappingSystem - My code mapping system..
AcecoolHotfix - Fixes issues in other mods - the goal, have 1 fix currently..
All Autocomplete - Unknown
AutoHotkey - lang
Batch File - lang
BracketHighlighter - Useful
C# - lang
C++ - lang
Color Scheme - Default - Default
Color Scheme - Legacy - Default
ColorSchemeEditor - Useful
Compare Side-By-Side - have yet to use it
CSS - lang
Environment Settings - unknown
Extract Sublime Package - useful but not as useful as the other
GitHub Flavored Markdown Preview - have yet to use
GitHub Markdown Snippets - used to help with mapping markdown
GMod Lua - Lang
Highlight Duplicates - Useful when set to be subtle otherwise annoying
HTML - lang
HTML-CSS-JS Prettify - Likely going to remove, have been using web services
Java - Lang
jEdit Color Theme - unknown
JSON Reindent - unknown
JsonTree - Unknown
Keep Open on Last Tab Close - doesn't seem to work so I'll remove it
Language - English - spellcheck
LastModifiedIndicator - useful
Markdown - lang
Marking Changed Rows - useful
Modific - unknown
MySQL Snippets - to help when I map SQL
Open File in Current Folder - helper
Package Control - useful
PackageResourceViewer - better than extract
PHP - lang
Pretty JSON - unknown
Python - lang
QuickGotoAnything - Library?
QuickPanelEnhanced - Library?
QuickSearchEnhanced - Library? One of these 3 was downloaded for something which needed the others or something along those lines...
Regular Expressions - lang?
SendToPasteBin - Useful
ShellScript - lang
SideBarEnhancements - This may be a problematic plugin - I thought I removed it before or it was something else which cycled all of the open tabs... or this may be here for sidebar menu options...
SQFLanguage - lang
SQL - lang
StripHTML - unknown
SyncedSidebarBg - so sidebar is same color as theme
Text - lang
Theme - Default - Default
Theme - Night - Default
ThemeTweaker - useful
WordHighlight - useful
XML - lang