create_notification_key throws Error 500 Internal Server Error

when I run

@fcm = FCM.new(StringIO.new(ENV.fetch('FCM_AUTH_JSON_STRING')), ENV.fetch('FCM_AUTH_SENDER_ID'))
token = "yyyyyyyyyyyyyyyyyyyy:xxxxxxxxxxxxxdevicetoken"

notification_title = "asdf"
notification_body = "asdf"
notification_data_type = nil
message = {
  token: token,
  # token: fcm_device_group_notification_key,
  # 'topic': "yourTopic",
  # 'condition': "'TopicA' in topics && ('TopicB' in topics || 'TopicC' in topics)",
  data: notification_data_type ? { type: notification_data_type } : nil,
  notification: {
    title: notification_title,
    body: notification_body,
  },
}.compact
response_body = @fcm.send_notification_v1(message)

all ok

=> {:body=>"{\n  \"name\": \"projects/1003694490304/messages/1727410938098076\"\n}\n",
 :headers=>
  {"content-type"=>"application/json; charset=UTF-8",
   "vary"=>"Origin, X-Origin, Referer",
   "date"=>"Fri, 27 Sep 2024 04:22:18 GMT",
   "server"=>"scaffolding on HTTPServer2",
   "cache-control"=>"private",
   "x-xss-protection"=>"0",
   "x-frame-options"=>"SAMEORIGIN",
   "x-content-type-options"=>"nosniff",
   "alt-svc"=>"h3=\":443\"; ma=2592000,h3-29=\":443\"; ma=2592000",
   "connection"=>"close",
   "transfer-encoding"=>"chunked"},
 :status_code=>200,
 :response=>"success"}

but

os = "ios"

device_registration_ids = [token],

params = {
  key_name: "user-#{163}",
  project_id: ENV.fetch('FCM_AUTH_SENDER_ID'),
  registration_ids: device_registration_ids,
}
response = @fcm.create_notification_key(*params.values)

sometimes gives

=> {:body=>"<HTML>\n<HEAD>\n<TITLE>Internal Server Error</TITLE>\n</HEAD>\n<BODY BGCOLOR=\"#FFFFFF\" TEXT=\"#000000\">\n<!-- GSE Default Error -->\n<H1>Internal Server Error</H1>\n<H2>Error 500</H2>\n</BODY>\n</HTML>\n",
 :headers=>
  {"content-type"=>"text/html; charset=UTF-8",
   "date"=>"Fri, 27 Sep 2024 04:12:58 GMT",
   "expires"=>"Fri, 27 Sep 2024 04:12:58 GMT",
   "cache-control"=>"private, max-age=0",
   "x-content-type-options"=>"nosniff",
   "x-frame-options"=>"SAMEORIGIN",
   "content-security-policy"=>"frame-ancestors 'self'",
   "x-xss-protection"=>"1; mode=block",
   "server"=>"GSE",
   "alt-svc"=>"h3=\":443\"; ma=2592000,h3-29=\":443\"; ma=2592000",
   "connection"=>"close",
   "transfer-encoding"=>"chunked"},
 :status_code=>500,
 :response=>"There was an internal error in the FCM server while trying to process the request."}

but more often it gives

{:body=>"<HTML>\n<HEAD>\n<TITLE>Unauthorized</TITLE>\n</HEAD>\n<BODY BGCOLOR=\"#FFFFFF\" TEXT=\"#000000\">\n<!-- GSE Default Error -->\n<H1>Unauthorized</H1>\n<H2>Error 401</H2>\n</BODY>\n</HTML>\n", 
:headers=>{"content-type"=>"text/html; charset=UTF-8", 
  "date"=>"Thu, 26 Sep 2024 16:25:31 GMT", 
  "expires"=>"Thu, 26 Sep 2024 16:25:31 GMT",
  "cache-control"=>"private, max-age=0", 
 "x-content-type-options"=>"nosniff",
  "x-frame-options"=>"SAMEORIGIN", 
 "content-security-policy"=>"frame-ancestors 'self'", 
 "x-xss-protection"=>"1; mode=block", 
 "server"=>"GSE", 
 "alt-svc"=>"h3=\":443\"; 
 ma=2592000,h3-29=\":443\"; ma=2592000", 
 "connection"=>"close", "transfer-encoding"=>"chunked"}, 
:status_code=>401, 
:response=>"There was an error authenticating the sender account."}

decision-labs / fcm

create_notification_key throws Error 500 Internal Server Error #129