Y Capacitor Value Confusion
The replacement part is unlikely to be a Y capacitor.

The failure of a Y capacitor leads to an electric shock hazard, and no fuse blows. For example, a surge on the AC power line is likely to damage the Y capacitors. A typical surge might be due to a direct or indirect lightning strike.

All Y capacitors must have an AC rating. The 250V rating on the replaced part is an AC RMS voltage. In addition, there is a DC rating for types Y1, Y2, and Y4.
The original part is type Y2, which means that it has a DC rating of 5000V. I wouldn't install the replacement. Use a real Y2 capacitor.