Actually, I have been keeping toadstools for years.
Anytime that a toadstool slumps over for me it's because it is stressed.
Flow to strong?
lights should not matter much unless super strong
Water Parameters may be very different to previous
FYI, my parameters are:
Salt 1.026
7.7 alk
1250 mag
410 cal
nitrates 20ish
phos zeroish
For a leather, please focus on flow, lights, salinity, nitrates and phosphates.
a leather can spend months slumped over if water conditions are not ideal.
Eventually it can die.