The Druid Regeneration spell line overwrites the DB purchased Bottle of Replenishment. Was in a group where many of us had used the bottle of replenishment that we purchased from the DB store when our druid cast something from the regeneration line (Pack Chloroplast, regrowth, etc.) and the potion buff disappeared. Another occurrence happened when a "Good Samaritan" outside the group ran by and cast Pack Chloroplast on our group, and the 10 minute free spell overwrote our 5 hour purchased bottle buff. He wasn't even in our group. I feel the spells should NOT overwrite the potions that we spend real money money on.
I made changes to the purchased potions that should block all buffs that conflict. It needs a full patch to go in game (July 2020)
The Bottle of Replenishment is also overwritten by several necro DoTs. While it's frustrating in the extreme to have it overwritten by those, I don't know that blocking them would be less game-breaking.
I discovered this last night as well. I was running the NRO LDoN missions and popped a regen potion. About 10 minutes later, I noticed a empty spot on the buff bar...where the regen icon once was. Earlier, I had been hit by a mob clinging darkness type of spell that must have stripped my regen pot. I don't suppose a fella could get refunded for this, huh?