Hard to shift from 5th to 6th. But not from 6th to 5th.

This first happened back in Jan, and has gotten worst to where nearly all the time, I can't go from 5th to 6th.

So what I have done is to go from 5th to 4th, then to 6th, while holding the clutch down. This movement allows me to go into 6th gear.

I can also just go from 4th to 6th with no issues.

Other suggested that perhaps the shift bushing may be worn.

Please take a look at this pic. Do you visually see anything (else) wrong?

The bushings are the letter A, is that correct?

Also, because this is a used car and I don't know what it looks like new. There is a tiny gap in rubber part of A, right side. Is that the cause you think? It's the bushings?