SD-card not vissible in Basecamp

Hi,

I have a Zumo 350 with an extra SD-card installed.

In the past, when I connected the device to my laptop, both the internal memory and the SD-card was shown in Basecamp, and I could
select either location to send routes, maps,....
Lately only the internal memory location is shown in Basecamp.

The SD-cards is available when using Windows file explorer, and works fine under Windows.
Also the device can read the SD-card, as the maps which are installed on the card are available on the Zumo.

I tried reformating the card, but this did not help (as expected).

Any other ideas (besides reinstalling Basecamp, which I want to avoid)