The default port of the USB Agent for Biomini and DE-620 usage is port 8081 and 8082.
If those ports are being used by another service, you will not be able to see the devices in BioStar 2 because of the service port collision.
Before BioStar 2.6, there was a bug when changing the port number for the USB Agent.
Even if you changed it in the UI of Biomini USB Agent, it was not applied on the web client side.
Hence you would have to use a manual configuration option shown below:
[Known Issue] Biomini Agent / USB Agent Port Cannot be Changed
Changing Port Usage
From BioStar 2.6 you can change the port usage of USB Agent by following the steps below:
1. Search for USB Device Agent in the Windows start menu.
2. Right click on the USB Device Agent on the system tray.
3. Click Setup.
4. Change the http port and https port to the desired port number.
* Check that the port numbers are not being used by any other service.
5. Click Save.
6. Click Stop.
7. Click Start.
6. Click Enroll Certificates.
* Enrolling certificate is only necessary if you're using HTTPS and if you didn't enroll the certificate when installing USB Agent.
7. Click Yes when popups appear.
8. Log in to BioStar 2 web client .
9. Go to Settings > USB Agent.
10. Change the USB Agent Port Number to your USB Agent port.
11. Click Apply.
12. Click F12 to open Chrome developer mode
13. Right click on the circling arrow (refresh button).
14. Click Empty Cache and Hard Reload.
15. Log in to BioStar and check if Biomini is visible.