W176 tail light odd issue

[NotStig]

I’m hoping someone can help with an odd issue. I have a w176 2015 a class and I’m getting rear bulb failure warnings. The bulbs are fine, but when I press them right into the holder they go off. Pull them out a couple of mm and they go on. I’m assuming it’s a holder issue but without replacing the entire holder, can this be fixed?

I’ve tried to avoid putting something in the holder to raise the base of the bulb, but maybe that’s all I need. Suggestions please.

Thanks all