OPTIPLEX problems with HDMI connection

Hey! I have an organizational optiplex which is of my company, I’m working from home so I cannot enter any settings, they’re blocked. 15 days ago when I first got it here I connected it to a VGA monitor that is very small and to my tv with the hdmi to work more comfortably, it worked wonderfully, since two days ago I began to have problems with the HDMI connection and is not the cable, I tried with 3 different ones, is not the TV I tried with another one, and progressively got worse, two days ago I just had to disconnect it and connect it again like three times and that was it, yesterday I had to do it for half an hour and today I have been trying for 2 hours and it doesn’t work. It’s weird because today when I first turned ON the tv it briefly worked but then  rapidly it went to not working. I’m sure it is the PC because the VGA works perfectly and just two days ago the HDMI began to bother and is not hardware because when it works it doesn’t stop working is just when the PC or the TV is turned off or suspended. It’s like it doesn’t recognize it, even weirder is that with one HDMI cable it appears as the screen isn’t being extended but the tv does not project any image, IM veryy confused I cannot change settings so I don’t know what to do HELPPPPP!!!!!