Teranex Express - audio delay not compensated

We are using several Teranex Express, AV and 2D converters in our production and we noticed, that audio is not compensated for the video delay introduced during genlock to external sync. We have to manually add 1 frame audio delay. Only Teranex 2D is working as expected. We are using Valid 8 generator and reader for A/V offset assessment.
Software version is 6.1

Thanks