Questionable HC-05 & HC-06 boards on Market. Beware

alright, confirmed i'm, in fact, not crazy.
(this all started where an app I made some time ago on a new project would seem to work properly, BUT would freeze every half second or so, and then machine gun me the data from that half second - I tested this by incrementing by 1 in a test program every time I send data.
set to send a 10 strings per second, id see a rapid run from say 1 to 5, then a pause, then a run from 5 to 10, then another pause - and so on)
again, the scenario noted above happened on an app i've never had any problems with before on the same exact phone.

Left HC-05 connects easy and clean, accepts AT commands - flawless with 0 issues, 10 strings per second no problem or lag.

Middle-Left HC-05: wouldnt work at all. characters are skewed, so its definitely a different baud rate - but wouldnt take AT commands?. notice its the same chips but the soldered connections as well as top green board are different.

middle-right HC-05: same issues as noted at beginning of post - seems to momentarily freeze, and then Gatling gun the data every half second-ish or so. Baud is correct, takes AT commands no problem. notice again yet another back board config with this time completely different chips, although gold fingers soldered the same as the perfectly functioning first board.

right HC-06: ah yes, the one everyone tells me to use and that NOT using it is causing my problems. well, it does literally the same as the board noted above (middle-right). visually its also the same as the middle-right HC-05 board - solder connections and all. only difference being the lack of pins and AT mode button due to being an HC-06. bottom chip is different brand but appears same (the chip that on the middle-right HC-05 has a gold checkmark).

anyway, theres some real funk going on here - all of these were tested with literally the same app program.
Heres where im really raising my eyebrow though - on this Serial app, the chips that pause do NOT hesitate here. keep in mind this isnt an MIT app.

so is this a backend issue with some chips and mit app inventor compatibility?
is there just a ton of bad chips out there?

there has to be someone who knows - I would like to set the record straight so no one has to deal with this ever again. deserves a youtube video no doubt - exceptionally annoying issue.

BTW, this is the link to the HC-05 that worked 100 percent correctly: