Using I2C Light sensor, Temp/Hum Hi Accuracy sensor together

Hi all, first post to this forum, so thanks for developing so many great products!

I have been trying to use the I2C light sensor and high accuracy temp/humidity sensors together on the same base shield, connected to an arduino PoE board.

They work independently, but as soon as I plug them together I can’t get any serial output. I understand they already have different I2C addresses, so it should not be a problem, but I can’t get them to work together on the same board.

Any clues?