Update to Docker Version 5.5.3 (UNRAID hosted) broke installation

[40foot]

Bug description
I am running Firefly III version 5.5.3, and my problem is:

No bookings can be made, getting empty page, no new accounts can be made, also empty pages.

Steps to reproduce

Have to click 2 times on the new Plus-symbol (v2?) to get the menu, 1st click just loads the startpage, but also when the old plus is clicked, I get an empty page.

Extra info
UNRAID Ver. 6.8.3
MySQL Ver. 5.7.33

Debug information generated at 2021-04-05 02:42:07 Europe/Berlin for Firefly III version 5.5.3.

Scope	Version
Firefly III	5.5.3
Firefly III API	1.5.1
PHP	8.0.3
Host	Linux

System info	Value
Installation ID	7245832b-052a-425d-98d8-88f1059b373a
Using docker?	true
Telemetry	false
Layout	v2
TZ	Europe/Berlin
App environment	local
App debug mode	false
App cache driver	file
App logging	debug, stdout
Display errors	Off
Error reporting	ALL errors
Interface	apache2handler
Default language	en_US
Default locale	equal
BCscale	12
DB drivers	mysql, pgsql, sqlite
Current driver	mysql
DB version	16 (exp. 16)
Login provider	eloquent
Trusted proxies (.env)

User info	Value
Session start	2021-04-01 00:00:00
Session end	2021-04-30 23:59:59
Session first
User ID	1
User language	de_DE
User locale	de_DE
Attempt at "de_DE.utf8"	'de_DE.utf8'
Attempt at "de_DE.UTF-8"	'de_DE.UTF-8'
User agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36 Edg/89.0.774.63

DO NOT PUT BACKTICKS AROUND THE OUTPUT OF THE /debug PAGE

-->

Bonus points

I'm flabbergasted: on the demo-site there is this new menu missing and certainly everything works... How come? How can I get rid of this v2 Menu? Don't like the new style at all, to be honest... I was not able to return to any of the old versions without problems, so I have to stick to latest?

[JC5]

Well you can certainly go back to the original layout by not changing the FIREFLY_III_LAYOUT to v2. That's something you can do yourself.

[JC5]

I know nothing about Unraid itself I'm afraid. You'll have to ask them.