After some testing, and I don't know why this happens but when I have JEI installed, along with Bountiful, and Regeneration on top of each other JEI just disappears. I don't know if it's this mod's code or Bountiful' s or JEI, but I thought I should at least bring it to your attention just in case you could solve it.

Mods installed:
New Tardis
Regen
Bountiful + Kottle
JEI
JER
JEI Integration

Is this resolved?

Could you please send a video or screenshot that shows the problem more clearly?

Sure! I'll also provide the log just incase. https://paste.ubuntu.com/p/r5xp2pFjXB/

Left with Regen mod, right with out.

That's fine. I can't, really read those reports because it's a tad beyond me. :D But I like using both mods so, I wanted to at least bring it to your guy's attention. Thanks for the info and here's hoping it all works out. ^.^ Thank you for your time and I apologize for the inconvience.

Seems that there's a issue reading one of the loot tables, from both bountiful and Regeneration
com.google.gson.JsonSyntaxException: Expected name to be an item, was unknown string 'regeneration:arch'

and

[12:23:11] [Server thread/ERROR]: Couldn't parse loot table bountiful:blocks/bountyboard

Further down on the crash report, it seems there's another issue with bountiful
Seems it relies on Kotlin and some casting crash occurred, don't know much about Kotlin to say anything more on it, but I will fix my weird loot table later and see if that fixes the issue, else I don't see anymore leads for Regeneration