InDesign 2025/2026 freezing (not responding) with Paragraph Panel & multiple CEP HTML Engine instances, with possible file corruption

Hello, in short, what it says on the title: InDesign 2025/2026 freezes (ends up as “not responding” in the Task manager) when interacting with the Paragraph Panel or with other, simple interactions; there are also multiple CEP HTML Engine instances that are generated, and there might be a possible file corruption, though I couldn’t verify that. More information below:

SOFTWARE
InDesign 2026 (21.2).
Windows 10.

HARDWARE
CPU: AMD Ryzen 9 5900X 12-Core Processor 3.70 GHz.
GPU: NVIDIA GeForce RTX 3070 (8 GB).
RAM: 64 GB.
Storage:
(I installed Adobe apps on my D Drive),
233 GB SSD KINGSTON SA2000M8250G (C Drive, 70 GB of free space),
466 GB SSD KINGSTON SA2000M8500G (D Drive 155 GB of free space).

PROBLEM
Since late 2025 (I cannot pinpoint exactly from which version this started to happen) until now, the problem that I have been having is triple:

1. Merely invoking (trough the Window > Type & Tables > Paragraph), opening or selecting the Paragraph panel freezes the program (in the Task Manager it immediately appears as not responding by doing so). The resulting state lasts for various seconds or even a minute, making the program practically unusable, to the point of even closing the file taking roughly a minute, and closing the program requiring me to end the task with the Task Manager. Also, the program (and this program alone) got slow overall.

2. There appears to be an issue with the CEP HTML Engine that does not occur with every file, and sometimes it doesn't manifest even with the files that are possibly corrupted (se point 3): certain files cause a significant spike of multiple instances (sometimes even up to 23) of it being opened, whereas others did not cause this thing to appear in the task manager at all (though this happened only once). But in both cases, the program stops responding, even by simply opening them and doing nothing.

3. This, however, does not occur with every file. Instead, it occurs with specific files, but the particularly vexing aspect of this problem is that files that worked perfectly fine can start failing, even ones that aren't derived (duplicated) from the possibly corrupted ones. This generates an obvious uncertainty, since I do not know if a file, irrespective of it being brand new or old, will fail today, tomorrow, in a week or a in a month. And this happens even with incremental backups from back when they worked without any issues.

I have been unable to identify what triggers the issue. Also, this problem is particularly worrying, since big projects can become impossible to fix, so starting anew is not an acceptable option (by the way, copying the text in a new document doesn't break the new document, even after pasting it with formatting).

I don’t know what else to do.

ADDITIONAL CONTEXT
I have been using InDesign for quite a while without a single issue, and these files in particular have been working flawlessly, even after blackouts. They just spontaneously stopped working properly, and I have no apparent guarantee that it won’t happen with other files.

TROUBLESHOOTING ALREADY TRIED:
1. Turned Preflight off.
2. Restarted the program.
3. Reset preferences (Ctrl+Alt+Shift upon startup).
4. Updated drivers.
5. Reinstalled the program.
6. Creative Cloud Cleaner tool.
7. Revo Uninstaller (I deleted every single trace of Adobe from my system and reinstalled it all multiple times).
8. Saved the affected files as IDML and then back as INDD (I also tried packaging the INDD files). The problem persists even with the IDML files.
9. High CPU usage due to CEPHtmlEngine.
10. Opening the file in another computer (a laptop with similar specs; InDesign is installed in te C Drive in that one).
11. I downloaded Affinity just to see if it could handle the possibly corrupted files (in IDML), and it opened them just fine, without freezing, and without any performance issues whatsoever.

ADDITIONAL NOTES
Though I found some relevant variations of my problem in this forum, they all seem to be only partially relevant, for which I considered that it was preferable to open a new question thread. Nonetheless, I'll leave them for reference:
InDesign 2025 Freezing – CEPHtmlEngine.exe / libcef.dll Crash Issue
Paragraph and Character Styles very slow when making changes to an existing style, help!!
InDesign Freeze when Changing things in Paragraph Style
How to turn off CEP HTML Engine permanently?!
Multiple 'Adobe CEP HTML Engine' whenever using inDesign
Why so many processes of Adobe CEP HTML Engine running in background on Windows system.
High CPU usage due to CEPHtmlEngine
How to disable core CEP HTML Engine plugins (NOT 3rd party plugins)
What is the "Adobe CEP HTML Engine"? It`s using too much from my processor.

ATTACHMENTS
EXAMPLE FILE A (brand new, without issues).
EXAMPLE FILE B (possibly corrupted, it generates multiple CEP HTML Engine instances).
EXAMPLE FILE C (possibly corrupted, it initially did not generate CEP HTML Engine instances, but after testing it again, it did every time). I attached both the .indd and .idml.
Screenshots of the Task Manager.