Alertmanager started sending emails about InfoInhibitor alerts

A few weeks ago my alert manager started sending emails for InfoInhibitor alerts.
From my understanding of the configuration it should not do that and it did not do it before.
I do not remember exactly when it started so I cannot easily pinpoint the source of the issue.
Any assistance will be greatly appreciated

attached is the [redacted] config:

global:
  resolve_timeout: 5m
  http_config:
    follow_redirects: true
    enable_http2: true
  smtp_hello: localhost
  smtp_require_tls: true
  smtp_tls_config:
    insecure_skip_verify: false
  slack_app_url: https://slack.com/api/chat.postMessage
  pagerduty_url: https://events.pagerduty.com/v2/enqueue
  opsgenie_api_url: https://api.opsgenie.com/
  wechat_api_url: https://qyapi.weixin.qq.com/cgi-bin/
  victorops_api_url: https://alert.victorops.com/integrations/generic/20131114/alert/
  telegram_api_url: https://api.telegram.org
  webex_api_url: https://webexapis.com/v1/messages
  rocketchat_api_url: https://open.rocket.chat/
route:
  receiver: email receiver
  group_by:
  - alertname
  continue: false
  routes:
  - receiver: "null"
    matchers:
    - alertname="Watchdog"
    continue: false
  group_wait: 30s
  group_interval: 5m
  repeat_interval: 12h
inhibit_rules:
- source_matchers:
  - severity="critical"
  target_matchers:
  - severity=~"warning|info"
  equal:
  - namespace
  - alertname
- source_matchers:
  - severity="warning"
  target_matchers:
  - severity="info"
  equal:
  - namespace
  - alertname
- source_matchers:
  - alertname="InfoInhibitor"
  target_matchers:
  - severity="info"
  equal:
  - namespace
- target_matchers:
  - alertname="NodeDiskIOSaturation"
  - severity="warning"
receivers:
- name: "null"
- name: email receiver
  email_configs:
  - send_resolved: true
    to: [redacted]
    from: [redacted]
    hello: [redacted]
    smarthost: [redacted]
    auth_username: [redacted]
    auth_password: [redacted]
    headers:
      From: Alertmanager <[redacted]>
      Subject: '{{ template "email.default.subject" . }}'
      To: [redacted]
    html: '{{ template "email.default.html" . }}'
    require_tls: true
    tls_config:
      insecure_skip_verify: false
templates:
- /etc/alertmanager/config/*.tmpl

And an example email:

View in Alertmanager
[1] Firing
Labels
alertname = InfoInhibitor
alertstate = pending
container = homepage
instance = [redacted]
namespace = homepage
pod = homepage-57bdb44f85-jshr5
prometheus = monitoring/prometheus-stack-kube-prom-prometheus
service = prometheus-stack-kube-prom-kubelet
severity = none
Annotations
description = This is an alert that is used to inhibit info alerts. By themselves, the info-level alerts are sometimes very noisy, but they are relevant when combined with other alerts. This alert fires whenever there's a severity="info" alert, and stops firing when another alert with a severity of 'warning' or 'critical' starts firing on the same namespace. This alert should be routed to a null receiver and configured to inhibit alerts with severity="info".
runbook_url = https://runbooks.prometheus-operator.dev/runbooks/general/infoinhibitor
summary = Info-level alert inhibition.