Your wide range 11-32 cassette shouldn't be cross chained all the way at those speeds with both chainrings. I'm guessing your front derailleur isn't adjusted correctly.
You should be able to use 10 of the 11 cogs in the big ring, and 9 of the 11 in the small ring. (sometimes the chain makes a ticking sound against the pickup rivets on the side of the big ring when the small is cross chained.)

Counting from big to small, which cog are you on when it's making noise? Get the cog number for the big ring and for the small ring.

(For metric challenged USA viewers, your usual 25-30 kph is about 16-18 mph.)

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Even at low cadences, you shouldn't hear a cross chaining sound in both chainrings at the same speed.

Your 11-32 cassette at lower cadences. The 50 chainring is in black, the 34 in red:

If you were cross chaining in the 34-13 (which shouldn't make a noise) or the 34-12, then the 50 ring would use the 18 or 20 cog, right in the middle of the cassette.


Here's the chart at faster flat road cadences, near 90 rpm, typical for many riders.
The 25-30 kph range is near the middle of the cassette in either chainring.


The same in mph: