Lag in Instances + Endless "loading" screens when transitioning to a new area

[Acquitor]

-50 for Square Enix

This should have been tested and hotfixed in the 23ish hour maintenance that was done as they stressed the need for that time to make sure it was all perfect. (obviously it's not)
The new server setup that has been implemented has something seriously wrong with it.
Open world is fine (I haven't seen these endless loading screens but have had a couple friends have it)
This seems to be 100% confined to instance servers of all variations.
When it takes 3 minutes for an NPC or random item in a dungeon / guildhest to respond that's never a good sign.
All of these problems are new to this patch. The game ran like a dream with no hiccups for me pre-patch.
Every last person I run with has the exact same issues at the exact same times that I experience them.
It goes from bogged as heck for up to a few minutes to running fine for somewhere close to a few minutes.

Symptoms include but are not necessarily limited to:
- "Teleporting" players ... Players don't run any more. They teleport vast distances because of constant desynchronization
- Frequent red disconnect circle icons appearing beside player names in dungeons. This comes in blips when we're experiencing the issues.
- Inability to cast spells or abilities. You press the button and it doesn't respond at all. This can last a long time.. and as a healer this is irritating and dangerous.
- High Latency. During these long blips of trouble, IF you can get a spell off it generally comes at a huge delay. I'd gauge it somewhere close to 50/50 with misfirings or a completely lagged skill. This high latency also causes you to be hit by AOE / dodge mechanics that you've gotten extremely far away from by the time they go off but they still hit you.
- Much larger spikes when interacting with inanimate objects (doors, keys, chain pulls.. oh AND Dungeon exit portals) and NPCs which cause COMPLETE lockup for long periods of time.
- Instance servers -only-. I experience absolutely no problems in the open world and all reports I've seen/gotten from friends and fc mates have been in some variation of instance. (and yes it's ALL of the instance types) ---We all run on very high-tier self built PCs so there may be other problems affecting lower-tiered computers as well.---

This is EXTREMELY frustrating and I would appreciate it a lot if Square Enix could get this dealt with. I don't even care if it has to go down for another full day to fix it.
These dungeons/guildhests/story quests instances are absolutely horrendous and this should be a top priority fix.
This is a universal problem and it occurs with every person involved regardless of the home server they originated from.

Side note: This also seems to be getting worse with time. Yesterday, I only experienced half of these issues and in much smaller spurts.