As the title says after recent update, the block always sit on air when I want to place it on wall.

Its 2.6.3 , i always update to the latest through twitch client.
Its annoying this problem bcz you cannot use it with blocks above the receiver or below, The same for the transmitter.

Will be fixed in the next release of RFTools.

I assume you mean RFTools 7.24. What version of McJtyLib are you on? If not 2.6.3, try updating.

Thank you for the fix it helped but not every time I log in it reset to the sitting position.

Okay, it should be fixed for real this time.