Diesel Fuel Filter problem - white plastic cap on bottom fell off

[Garbon]

I went to see if there was any water in the diesel fuel filter today and the white cap on the bottom on the metal filter just fell into my hand There is a rubber washer with it as well, lucky I did not lose it on the floor...

I can't seem to get it back on the bottom of the filter

Is it supposed to be a contortionist manoeuvre or what?

I may have to remove the filter from the housing tomorrow just to try and figure out how to attach the white cap on the base of the filter

Anyone else had this problem?

Been busy with the car today as you can see from my posts

[Garbon]

Went to Repco and bought a replacement fuel filter, fitted it this afternoon

All good now