I am not sure if this guys mod will fix it for you as a work around, it seems to be listed.
Volcano Tree Fix (global) for Microsoft Flight Simulator | MSFS
Krakatoa, Indonesia
Pangrango, Indonesia
Ciremai, Indonesia
Raung, Indonesia (quite a nice one)
Gunung Merapi, Indonesia
Mount Merbabu, Indonesia
Agung, Bali
Mount Tambora, Indonesia (quite a nice one!)
Mount St. Helens, Washington state
Mount Rainier, Washington State
Mount Pelée, Martinique
Mount Pinatubo, Philippines
Mount Mayon, Philippines
Thera, Greece
Mount Stromboli, Italy
Mount Misti, Peru
Telica Volcano, Nicaragua
Izalco, El Salvador
Arenal volcano, Costa Rica
Poás volcano, Costa Rica
Irazú volcano, Costa Rica
Mount Vesuvius, Italy
Mount de Porri, Italy
Mount Fossa delle Felci, Italy
Piton de la Fournaise, La Réunion Island (quite a nice one!!)
Faeroe islands (all islands)
Teide (Tenerife, Canary Islands)
Taburiente (La Palma, Canary Islands)
Puy de Dôme, France
Puy de Sancy area, France
Taranaki (New Zealand)
Ruapehu (New Zealand)
Ngauruhoe (New Zealand)
Tongariro (New Zealand)
Pacaya, Guatemala
Sajama, Bolivia
Nyiragongo, Kongo
Ol Doinyo Lengai, Kenya
Kilauea & Mauna Loa, Hawaii
Popocatépetl, Mexico City
Mt Hood (Oregon, USA)
Mt Shasta (CA, USA)
Lassen-Modoc volcanic center (CA, USA)
Crater Lake (Oregon)
Three Sisters (Oregon, USA)
Mammoth Mountain (USA)