Reverse Polarity on rear bulbs

[Shugalou]

Something strange is going on when I went to replace a burnt out bulb in the rear. The signals stopped working and when I put the bulb in the wrong way the signal will work but when I seat it correctly it doesn't work.

I will be checking grounds in a few minutes but wondering if anyone else have insight into this.

Everything worked fine before the I tightening some bed bolts...Hoping it's an easy find/fix.

Thanks