Noticed the same problem today.
After some digging I found that the dependency extension Cortex-Debug received a major update from v0.3.13 to v0.4.0 on 11/08/2021. As described in the already mentioned issue, I installed the previous version (v0.3.13) of the Cortex-Debug extension.
This solved the problem, I guess until the particle devs update their own extension accordingly.