[Evolution] Evolution 3.44.4 signature script not working

[Andre Truter <linux trusoftdev za net>]

Hallo,

I installed evolution 3.44.4 using the Flatpak from Flathub.org on
OpenSUSE Leap 15.3. (The distro version is 3.34, but that does not work
with Google Calender and addressbook)

I exported by config from 3.34 and then imported it again in 3.44.
Everything seems to be working fine, except my signature script.

I ran evolution from the command line to see what errors are printed
and it complains about the signature directory that does not exist, but
it does.

This is the messages in the terminal:

--<snip>--
/home/andre/.var/app/org.gnome.Evolution/config/evolution/signatures/1119988152.14239.2@vitalstatistix
: line 5: cd: /home/andre/signature: No such file or directory
ls: cannot access '*.inc': No such file or directory
ls: cannot access '*.inc': No such file or directory
cat: basic.sig: No such file or directory
--<snip>--

But the directory exist:
--<snip>--
andre@vitalstatistix:~/signature> pwd
/home/andre/signature
--<snip>--

And if I run the signature script in a terminal, it works:
--<snip>--
andre@vitalstatistix:~>
/home/andre/.var/app/org.gnome.Evolution/config/evolution/signatures/1119988152.14239.2@vitalstatistix
Andre Truter  | Software Consultant | Registered Linux user #185282<br>
Jabber: andre truter gmail com    |  
http://track.smtpsendemail.com/9098234/c?p=YMlHL5QF5CQ4Ha_bxqRhTgzI3Eyj1vSJoKjnOOqEl3zIRnBd9EZGbaemylyYY7EO1ZhXNXdtQpSMJlpxQ7Gh2nBkK1TscqSJXW0X4xYHWeIN1gVmc3qIpSNQgkZ9xlksunNLGu5hlHZsfyq79cpmiQ==<br>
<br>
~ My software never has bugs. It just develops random features. ~
andre@vitalstatistix:~> 
--<snip>--

So it only fails when run by Evolution.
Any ideas as to why it cannot access my signature folder?

I also tried to edit the signature setup in Evolution, but when I try
to open the file browser to select the script, nothing happens.
I get this error in the terminal:

--<snip>--
(evolution.bin:26): evolution-util-CRITICAL **: 19:41:27.269:
e_mail_signature_script_dialog_set_symlink_target: assertion
'symlink_target != NULL' failed

(evolution.bin:26): GLib-CRITICAL **: 19:41:29.291:
g_variant_new_string: assertion 'string != NULL' failed

(evolution.bin:26): Gtk-WARNING **: 19:41:29.293: Can't open portal
file chooser: GDBus.Error:org.freedesktop.portal.Error.InvalidArgument:
invalid filter: no filters

(process:345): Gtk-WARNING **: 19:51:34.343: Locale not supported by C
library.
        Using the fallback 'C' locale.
Gtk-Message: 19:51:34.343: Failed to load module "canberra-gtk-module"
--<snip>--

Thanks
Andre Truter