You could buy a better aerial plug made out of metal rather than the cheaper aluminium that most stores sell (maplins is a good source) and it would be slightly thicker, or a cheap option would be to try wrapping foil around the plug you’ve already got and see if it works.
Hi @Bluenwhite17 and welcome.
2 good suggestions form @Sava57. Personally I would replace the cable connector with a new metal one.
Cheers
David
Yes it’s always better to upgrade your aerial connection, all my aerial plugs are made out of the higher quality metal type and also I’ve changed all aerial wire for higher end satellite cable as it retains more of the signal from the Aerial to the TV.