Were there Jewish religious movements/sects in the history that used to put or hanged their Tefillin on their chest/neck? (rather than on the arm against the heart).
As far as I remember, I read in past, that there some sects to interpret "וְהָיוּ הַדְּבָרִים הָאֵלֶּה אֲשֶׁר אָנֹכִי מְצַוְּךָ הַיּוֹם עַל לְבָבֶךָ" to have Tefillin right on the chest in front of the heart. Probably some of them also based their idea on "קָשְׁרֵם עַל-גַּרְגְּרוֹתֶיךָ, כָּתְבֵם עַל-לוּחַ לִבֶּךָ".
Now I'm looking for information about it, and I found nothing.
You are probably misinterpreting the Karaite belief that caused them not to wear tefillin at all. They decided to pretend that the Rabbis invented tefillin for some unknown reason and that the actual command was to be reinterpreted as a metaphor. As explained by a Karaite blog Nehemia's Wall Tefillin (phylacteries)
In light of these verses the real meaning of the "Tefillin" passage
"And let these things which I command you today be upon your heart...
and you shall tie them for a sign upon your hand and for a
remembrance (Totafot) between your eyes and write them upon the
doorposts of your houses and your gates" (Dt 6:8-9)
The Torah is to be like a fine bracelet or necklace which we are to
wear proudly. In other words, the Torah is supposed to be precious to
us and be remembered always. It is worth noting that of the four
places in the Torah which use this expression 2 of them are telling us
to remember the Torah (Deuteronomy 6:8-9; 11:18) while the other two
are commanding us to remember the Exodus from Egypt (Exodus 13:9, 16).
It should be noted that the Karaites also interpret the verse "And you
shall write them on the doorposts of your houses and your gates"
(Deuteronomy 5:9; 11:20) to be a metaphor equivalent to "write them
upon the tablet of your heart." (Prv 3:3) and not as referring to the