ASCII representations:

Screen:

XPMMBIWZ
BPFPICPC
CRPMTDXX
RVUYJBTZ
FBTXGMWI
AWKISAIL
ZCFMIVPM


Info screen:

RABCC   RABCC
ZALBH   ZZKAH
ANUME > AMTLE
PIDON   PHCNN
CBBFL   CBBFL

• (I've just deleted quite a lot of discussion, much of it a bit intemperate, around the use of real people's names and chat avatars saying horrible things as backstory. My apologies if anyone feels that their pearls of wisdom have been censored :-). There's some discussion in TSL chat if anyone wants it.) – Gareth McCaughan Dec 27 '20 at 20:50
• Oh no where did the story go? – Dmitry Kamenetsky Dec 30 '20 at 0:18
• The story was removed because multiple people involved were uncomfortable. It's still there in the edit history if you really want to see users say horrible things they never would in real life. – bobble Dec 31 '20 at 1:18
• @bobble Are you serious? Why are you attack me like that again? I can't believe it. I flagged your comment and I hope this is the end of this. – Avigrail Dec 31 '20 at 9:16
• @DmitryKamenetsky elements in the story made people feel uncomfortable and offended. Thus it was removed. – Avigrail Dec 31 '20 at 9:33

The instructions tell us

that we should trace the message "your heart" on the keyboard. The info screen suggests that each key press will use rot25 for the pressed letter and all the adjacent ones (rotating each letter backwards A->Z, B->A etc.). There is only one place where to start the message

After that we continue finding the next letters in adjacent squares

In the picture above, we have to choose carefully between the two possible R, because only one of those makes it possible to advance to an H next.

Here we notice that OP has also hidden their own name in the puzzle. Again, we have to choose the E which allows us to advance the message.

And we finish with the same square with which we started giving

Inside the heart symbol, we find the hidden code: PSE

• Correct! Well done :) – Avigrail Dec 28 '20 at 17:33

Not an answer yet, but I'm writing down everything I notice and hoping it'll come to me

Info screen:

It looks like a lot of the letters are just shifted back one along in the alphabet (assuming it loops so ...uvwxyzabc...). The first and last rows aren't shifted at all though.
RABCC RABCC -- 0 0 0 0 0
ZALBH ZZKAH -- 0 -1 -1 -1 0
ANUME > AMTLE -- 0 -1 -1 -1 0
PIDON PHCNN -- 0 -1 -1 -1 0
CBBFL CBBFL -- 0 0 0 0 0

Screen:

The screen isn't the same size so I'm not sure how the rule from the info screen applies exactly. It could be scaled up but I noticed the second to last line AWKISAIL looks a lot like the OP's name and originally this was a story about them. Lets see if that looks like a key.
AWKISAIL > AVIGRAIL 0 -1 -2 -2 -1 0 0 0

Not sure there - might just be chasing a red herring. Shifting everything by one as in the previous example (just expanded) gives:
XPMMBIWZ
BOEOHBOC
CQOLSCWX
RUTXIASZ
FASWFLVI
AVJHRZHL
ZCFMIVPM
Wow, not helping in the slightest. What I was hoping for, from the "follow your heart" clue, was something like HEARTABC where ABC would be the three letter solution.

I feel like the AVIGRAIL bit is closer but I'm not yet sure how the rule translates.

• I suspect your observations need to be combined here to infer that rot13(cerffvat n yrggre ba gur fperra (vaqvpngrq ol gur yvtugre plna pbybhe va gur vzntr) unf gur rssrpg gung gung yrggre naq nyy bs vgf rvtug vzzrqvngr arvtuobhef ner fuvsgrq onpxjneqf ol 1 va gur nycunorg. Vg vf cbffvoyr gb ernpu NIVTENVY va gur crahygvzngr yvar guebhtu 2 pnershyyl pubfra cerffrf - V fhfcrpg jr jvyy arrq gb cerff shegure yrggref nebhaq gur tevq gb erirny n pbzcyrgr zrffntr, nygubhtu vg vf uneq gb frr ubj gb unir zhpu rssrpg ba gung obggbz yvar...) Hopefully someone can work with this! :) – Stiv Dec 28 '20 at 12:00
• @stiv ah, I hadn't actually looked at the linked image for the info screen, only the ASCII version. – Lio Elbammalf Dec 28 '20 at 13:42
• For what it's worth, my interpretation was the same as Stiv's. – Gareth McCaughan Dec 28 '20 at 14:26