Sorry, didn't find time because of the nice motorbike weather...now this evening, I executed the "Addon Manager.exe" from your link (after stopping Kaspersky):
No change. Starting P3D 4.5 HF3 shows "Couatl Debug Window" ~30 seconds after the P3D splash screen appeared.
Same content as before:
Python 2.7.16 Stackless 3.1b3 060516 (default, Mar 9 2019, 21:32:11) [MSC v.1500 64 bit (AMD64)] wxPython 3.0.2.0
couatl v4.8 (build 4800)
log started on Mon Aug 22 20:01:52 2022
connecting to SimConnect...
connected to SimConnect
bglmanx non ready yet, waiting.
connected to bglmanx
View changed to Virtual Cockpit
I checked the add-on.xml:
<?xml version="1.0" encoding="utf-8"?>
<SimBase.Document Type="AddOnXml" version="4,0" id="add-on">
<AddOn.Name>FsDreamTeam Addon Manager</AddOn.Name>
<AddOn.Description>FsDreamTeam Support software</AddOn.Description>
<AddOn.Component>
<Category>DLL</Category>
<Path>C:\Games\FSDT\Addon Manager\bglmanx64.dll</Path>
<DLLType>PDK</DLLType>
</AddOn.Component>
<AddOn.Component>
<Category>Scripts</Category>
<Path>C:\Games\FSDT\Addon Manager\Scripts</Path>
</AddOn.Component>
<AddOn.Component>
<Category>Effects</Category>
<Path>C:\Games\FSDT\Addon Manager\Effects</Path>
</AddOn.Component>
<AddOn.Component>
<Category>Sound</Category>
<Path>C:\Games\FSDT\Addon Manager\Sound</Path>
</AddOn.Component>
<AddOn.Component>
<Category>SimObjects</Category>
<Path>C:\Games\FSDT\Addon Manager\Simobjects\Misc</Path>
</AddOn.Component>
<AddOn.Component>
<Category>SimObjects</Category>
<Path>C:\Games\FSDT\Addon Manager\Simobjects\PBR</Path>
</AddOn.Component>
<AddOn.Component>
<Category>EXE</Category>
<Path>C:\Games\FSDT\Addon Manager\couatl64\Couatl64_P3D.exe</Path>
</AddOn.Component>
</SimBase.Document>
Then I checked the signature of the above C:\Games\FSDT\Addon Manager\bglmanx64.dll:
Name: VIRTUALI Sagl
Signing time: Saturday, August 13, 2022 11:43:25 PM
Details - File version: 5.0.0.4
Date modified: 8/13/2022 11:43 PM
Original filename bglmanx.dll
Checked also couatl64_P3D.exe:
Name: VIRTUALI Sagl
Signing time: Friday, August 19, 2022 1:31:41 PM
Details - File Version: 4.8.0.4800
Date modified 8/19/2022 1:31 PM
Original filename: Couatl.exe
But...as it's not a critical problem in my case (I simply left the Couatl Debug Window open while flying - on a short flight, I didn't notice any side effects in P3D) and I use GSX very rarely and even don't use P3D every day, you may care about other problems with higher priority first.