Panner gets bigger over time ?

Hi, I am using a Panner node in my material. I simply set speed to 0.003 and 0.002.
I package the project to ATC format and test it on Samsung Galaxy S5,
after playing for 5minutes and more , the gaps on texture panning get noticeable and get bigger over time,
like at start the panning is super smooth, and after 30min it looks like texture would be jumping,
now I can’t be sure this is caused by the time, and I don’t know really what is causing this,
the fps in game is always at 60, and the game runs smooth on the phone… however I didn’t notice this ever when testing on Windows7??
Also this problem seems unrelated to the engine version, it was same in 4.10 version as it is in 4.14.
I tried a few things, now I’m thinking to do it with C++ and move the texture coordinates each tick.
Any ideas??

Well the problem was that this actually happens with the water mesh, all the levels in my game are played at same location in 1 map, the rest of actors and characters are spawned and destroyed each level, it didn’t occur to me to do the same with the water mesh, just spawn and destroy it each level, so this way the effect of panner getting bigger over time won’t be noticed. However the problem is still there…

I’m reopening this question for now.
I did what I mentioned above, now I destroy and spawn the water mesh each level played, however the problem is exactly the same, which suggest this is caused by the “game time” (needed by the panner node to calculate the position of UVs) and the way it is calculated on the phone.
Something obviously gets off over time and the only way to reset this is to reset the whole map or load another one. I will think about it some more…

yes i am also experiencing this