Hello,
I am using nRF5340 DK, I was trying to connect it to my laptop MacBook Pro M2 but I continuously get this notifications about JLink disconnecting and reconnecting again, however I was able to flash a board. I know this is well known subject for MacOS, I tried some methods from other tickets like changing the JLink version, using Universal software, updating using brew, changing the cable and none of those helped. As I was reading about this problem on community I found a video of one of the users and my problem seems to be exactly like his: link to video. I work on MacOS Sequoia 15.5, using direct USB C - micro USB cable without any Hub.
Hope to hear from you soon,
BR
Antek