First it generated when you just log in or create the entity.
Tetra test OK
{F7047}
Wedge test OK (it's slighty cut but it's ok)
{F7045}
Corner test OK
{F7049}
Slab 1 test OK
{F7051}
Slab 2 test OK
{F7053}
Slab 3 test OK
{F7055}
But then after a certain amount of time the plumes turn off suddenly and are not coming back (even if remove-reput the thruster block in same place).
{F7043}
{F7059}
{F7061}
Maybe related to T208 and/or T898.