Problem With monitor or Grapics card

About 2-3 weeks ago bought 3 dell ultrasharp u2515h and i have been getting some weird problems.

monitor 1 (left) connected via dvi-d to HDMI adapter :
I have been getting some matrix looking green stripes all over the screen
these stripes only appear on a black background. and they will disappear if i restart the screen.

picture 1:https://gyazo.com/8299a2e146e10963607f60b8a0567f9a
picture 2: https://gyazo.com/53c1f730d2562baa171d638acf5add64

Monitor 2 (middle) connected via HDMI: Never had any problems.

monitor 3 (left) connected via dvi-d to hdmi addapter:
on this screen it seems like some of the pixels get lost in some way. there also appear to run black lines across the monitor only 1 or 2 pixels wide. the matrix stripes has also happened on this screen but only ones.

picture 1 how it normally looks like: https://gyazo.com/731efbe4ef0c1c098b456b2f50c605d8
picture 2 the problem: https://gyazo.com/8dad9741bcb7b93701e1565345c949d4

Thes problems only happens on startup, but only 1 of 3 ish time. and if i remove the error (by restarting the screen) they will not come back until i turn the computer off, this is why i think it may be a driver or hardware problem with the graphics card. I have the hole ting connected to a gtx 970.

do you have guys have any suggestions?

Has this always been a problem with the monitor.

since i got them, yes. never had any problems with the old one

have you swapped the cables between monitor 1 and 3 ?

i did that this morning. have restarted the computer a couple of times but the error has not occurred.

we shall give it some time and see if it appearers. I might be the DVI over HDMI and vice versa and the monitor driver is having issue.