I work regularly on large boats.

I always hand catch the drone after filming. To do this, I have always had to match the speed of the boat and lower the drone to just above deck height. Once the downwards facing sensors saw the deck as 'ground' it stayed stationary with the moving boat and was easy to reach out and grab it.  

Now I am on a different ship and the sensors are not responding like this. I suddenly have to use right stick to match speed of boat and left stick to lower drone within reach. Damn hard work. I can't land the drone on a moving platform and releasing the sticks to grab the drone is tough. Add to this, when I have the legs in my grasp, when I go to power down the drone, it reall starts fighting me.

So, any idea why the sensors are behaving differently now? The decking has similar pattern for the sensors to latch on to...

Is there a change to the new software update? Have I inadvertently turned sensors off?

Cheers in advance.

The Visual Positioning System of the drone can only work on grounds with irregular/non-repetitive patterns with good lighting condition. This feature has not changed with firmware update.

So the patterns of the decks of the two ships must be different, or the lighting is different.  I suggest you put something on the deck to make it look irregular. For example, you can carry two pieces of paper/blankets/tower of different shape/size (VPS is color-blind) and put them where you plan to land.  Or you can land the drone somewhere on the deck that has things can be identified by the drone, for example, next to a chair/pole on a deck.
That should solve the issue.

Thanks for your reply DJI-H.C.

The deck of the boat could not be more random. I am talking of piles of ropes, anchor mechanisms, railings, deck chairs etc.

I remembered that when I updated to the latest firmware, all the settings were reset to factory settings and I had to reapply my own settings to the camera (RAW, D-Log etc...)

I then had a look through all the other settings and saw the 'Multiple Flight Modes' toggle in the Basic settings menu of the Main Controller Settings was not on. I switched this on and noticed when I took off from the deck  that it held course with the boat. Hooray! It seemed to work!

However, when I brought it back to land, same issue. As always I would stand on the front deck, lower the drone in front of the bow of the boat and allow it to drift (no stick input) back to the boat. Before, when it passed over the top of the deck, the VPS would kick in and it would hold a position with the boat, allowing me to reach out and grab it. It still wouldn't. You can only imagine what it is like to hand catch a drone from a moving platform. Landing would be impossible.

Wondering if the vps camera isn't focusing, you probably already have, but clean the sensors and calibrate on the PC. I didn't even know the vps would lock onto a moving object so well as you had it, good to know.. as long as it works again!