packet manager "wait long" time before start downloading

from time to time i got long delay (few minutes), after i click install button in Package Manager.

is there any way to fix this ?
is this problem caused by my internet connection ?

i found UnityPackageManagerDiagnostics but in thered with this program i dont found any solution.

4 out of 6 checks passed:
[
  {
    "name": "UPM registry reachable",
    "description": "Make an HTTP request to the UPM package registry",
    "result": "PASS",
    "detail": "HTTP/1.1 200 OK\nX-Powered-By: Express\nProvider: Genesis\nDate: Mon, 17 Feb 2020 14:41:11 GMT\nConnection: close"
  },
  {
    "name": "Ping UPM registry",
    "description": "Measure the latency of the UPM package registry API",
    "result": "WARNING",
    "detail": "4 pings made in 5.03 seconds\nAverage latency: 193.23 ms\nMinimum latency: 168.26 ms\nMaximum latency: 209.09 ms\nStandard deviation: 19.58"
  },
  {
    "name": "Ping UPM download",
    "description": "Measure the latency of the UPM package download endpoint",
    "result": "WARNING",
    "detail": "4 pings made in 6.261 seconds\nAverage latency: 104.96 ms\nMinimum latency: 84.91 ms\nMaximum latency: 118.59 ms\nStandard deviation: 14.91"
  },
  {
    "name": "UPM registry download speed",
    "description": "Test the Internet connection using the UPM package registry",
    "result": "PASS",
    "detail": "Measured speed to the UPM registry: 4.21 Megabits per second"
  },
  {
    "name": "Speedtest.net",
    "description": "Test the Internet connection using Speedtest.net",
    "result": "PASS",
    "detail": "Measured speed to the Speedtest.net server: 3.49 Megabits per second"
  },
  {
    "name": "HTTP proxy environment variables",
    "description": "Detect whether proxy-related environment variables are set (HTTP_PROXY, HTTPS_PROXY, ALL_PROXY, NO_PROXY, UNITY_PROXYSERVER, UNITY_NOPROXY)",
    "result": "PASS",
    "detail": "No proxy support has been configured through environment variables."
  }
]

Sorry you are experiencing this delay. We are taking a look at it, thanks for reporting!

From the report, it looks like it. See Ping UPM registry and Ping UPM download tests result.

Regards,

Pascal