strava.client(access_token) broken in v4?

[pro-sumer]

This code was working fine with v3:

import strava from 'strava-v3'
...
strava.client(access_token)
strava.config({
  client_id: ...,
  client_secret: ...,
  redirect_uri: ...
})
...
await strava.athlete.listActivities({ 1, per_page: 50 })

However, with v4 I get a 401 from Strava and I noticed that the library sends Bearer undefined...

This seems to work:

import strava from 'strava-v3'
...
strava.config({
  access_token: access_token
  client_id: ...,
  client_secret: ...,
  redirect_uri: ...
})
...
await strava.athlete.listActivities({ 1, per_page: 50 })

I didn't read anything about this in the release notes.

What am I doing wrong? Or what did I miss?