sls deploy failed: Unknown Error From API: socket hang up

[Jonarod]

Everything was working fine until yesterday for no apparent reason I can think of. I woke up, made a change to my action, then ran sls deploy, and got this error:

Serverless: Packaging service...
Serverless: Excluding development dependencies...
Serverless: Compiling Functions...
Serverless: Compiling Packages...
Serverless: Compiling API Gateway definitions...
Serverless: Compiling Rules...
Serverless: Compiling Triggers & Feeds...
Serverless: Compiling Service Bindings...
Serverless: Deploying Functions...
 
  Serverless Error ---------------------------------------
 
  Failed to deploy function (backend-prod-register) due to error: Unknown Error From API: socket hang up
 
  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues
     Issues:        forum.serverless.com
 
  Your Environment Information ---------------------------
     Operating System:          linux
     Node Version:              12.9.1
     Framework Version:         1.52.0
     Plugin Version:            2.0.0
     SDK Version:               2.1.1

I tried to switch Node versions from 12.9.1 to 10.15.1: same issue.
I tried to delete serverless and reinstall it globally: same issue.
I tried to delete node_modules, package-lock.json and .serverless: same issue.
I tried to delete ~/.wskprops and regenerate it: same issue.
I tried to create a new helloworld project from scratch: same issue.

Even to print my versions using sls --version it first prints correctly but then keeps hanging for 2 minutes without quitting, I have to manually Ctrl+C.

A similar issue has already been solved here: #156 but I am working at home, with my router, and I don't remember using any proxy/firewall rules specifically blocking serverless services. Moreover, it was working fine until yesterday...

Would love any support to trace the origin of this issue.