Disconnects on One Character since 6.55

Hi there! I was hoping for some help as this is really perplexing me.

Ever since the launch of 6.55 I get 90001 disconnects on my main character. Since that usually pertains to a faulty connection I've done everything in my power to fix it. Port forwarding, DNS flushes, firewall disables, using a wired connection, uninstalling and reinstalling the game... if it's been suggested in this forum as a fix I've done it to no avail. I've spoken to other friends on my data centre who live in my country with the same ISP and they are experiencing no issues. I did speak to another in game friend from the States who has also confirmed they're having the same issue.

I've discovered that this only affects one character I have out of five. I was logged into one for three hours with no disconnects but the moment I swapped to my main, she'd disconnect after roughly 20 minutes no matter what I'm doing. Trials, roulettes, crafting, afking... no matter what. I've tried a few others and they are all able to hold a connection for over an hour so it's definitely to do with just the one. Whenever she disconnects nothing else I use that requires an Internet Connection pauses/needs rebooted.

I've tried to delete all files in My Games which made no difference, nor did importing a backup set of hotbars I have for her. I have no idea what's causing it but it does feel like it's more on Square's side than mine since surely it'd disconnect all my characters if it were my connection?

Error messages received (If applicable): 90001
Wired or WIFI connection?: It occurs with both
Are there other programs being used when running FFXIV?: Steam, Discord, Spotify
When the disconnect occurs/How often?: Every 20 - 30 minutes like clockwork
Does this only happen to one character or all characters?: Only one character

Thank you so much for any help or advice!

Good morning! Thank you for posting in the Final Fantasy XIV Technical Support Forums.

Please try the following:
- Update and reinstall the drivers for your graphics card and sound drivers (if applicable).
- Please try lowering the resolution.
- Please try running the game as an administrator.
- Perform a clean boot by opening the task manager and select the 'Start up' Tab. Disable everything.
- Please be sure that Final Fantasy XIV is installed to the C: Drive. (If Steam version, make sure both the game and Steam are installed on same drive)
- Please be sure to disable or remove any overlays (Discord, Steam, NVIDIA etc.) as they may interfere with startup. Please disable any programs that may be running in the background of the PC, including anti-virus programs.
- If you use OneDrive, please try removing the locally saved files there instead. You would follow the same general path: 'Documents' > 'My Games' > 'FINAL FANTASY XIV - A Realm Reborn' but under OneDrive rather than 'This PC'.
- Make sure that the Windows OS is fully updated.
- Verify installation files (Steam)
- Reinstall game (If steam version, try uninstalling and reinstalling both the game and Steam)

Thank you once again for visiting the Final Fantasy XIV Technical Support Forums!