After update to 6.4.2.2: Split database only accessible while running in Safe Mode

I updated LibreOffice from 6.0.7 to 6.4.2.2 via ppa:libreoffice/libreoffice-6-4. Now I get an error when trying to open a form in a HSQLDB 2.3.2 split database: “Error in script file line: 1 Unexpected token UNIQUE, requires COLLATION in statement [SET DATABASE UNIQUE]“

When running in Safe Mode, I can access the database. But even when using a new, clean profile, I can't access the database!

When starting LibreOffice with
LC_ALL=C libreoffice

I can open a form within the database but then an error like
“The data could not be loaded. There exists no table named "[Name of my table]".“ is displayed.

I tried installing the DEB packages provided on https://www.libreoffice.org/download/download/ , same version 6.4.2.2, and there the split database is working as expected.

I reported this bug wrongly first here:
https://bugs.documentfoundation.org/show_bug.cgi?id=132009

Steps to Reproduce:
1. Update LibreOffice from 6.0.7 to 6.4.2.2 on Ubuntu 18.04.4 using https://launchpad.net/~libreoffice/+archive/ubuntu/libreoffice-6-4
2. Start LO and open a split database (Use this test database: http://bugs.documentfoundation.org/attachment.cgi?id=159465 )
3. Click on a table

Actual Results:
Seeing following error message (when using German localization as normally)
“Error in script file line: 1 Unexpected token UNIQUE, requires COLLATION in statement [SET DATABASE UNIQUE]“

When starting LO with
LC_ALL=C libreoffice

I can open a form within the database but then an error message like
“The data could not be loaded. There exists no table named "[Name of my table]".“ is displayed.

So the database is not usable at all.

Expected Results:
The split database should be accessible.

Reproducible: Always

User Profile Reset: Yes

OpenGL enabled: Yes

Additional Info:
[Information automatically included from LibreOffice]
Locale: de
Module: OfficeDatabaseDocument
[Information guessed from browser]
OS: Linux (All)
OS is 64bit: yes
Version: 6.4.2.2
Build ID: 1:6.4.2-0ubuntu0.18.04.3
CPU threads: 4; OS: Linux 4.15; UI render: default; VCL: gtk3;
Locale: en-US (C); UI-Language: en-US
Calc: threaded

Ubuntu 18.04.4 LTS