The problem was solved in a strange way. I wanted to find out which folder or file was responsible for the mask settings. I deleted all the files located in the root of this folder: Documents\Adobe\Premiere Pro\26.0\
But I left the Settings folder and other folders alone. When I launched the program, the files from the OneDrive folder were loaded, and the mask appeared!!!!!!!!!!!!!!! Now I can see the mask. All I had to do was delete and reload the files from the Documents\Adobe\Premiere Pro\26.0\ folder
Intel Core i7-14700K 3.4GHz/33MB s1700 BOX MSI MAG Z790 Tomahawk Max Kingston Fury DDR5-6400 65536MB PC5-51200 be quiet! MSI PCI-Ex GeForce RTX 5070 Ti Gaming Trio OC 16GB GDDR7 SSD Samsung 990 Pro 2TB M.2 PCIe 4.0 x4 NVMe 2.0 V-NAND 3bit MLC SSD Samsung 990 Pro 1TB M.2 PCIe 4.0 x4 NVMe 2.0 V-NAND 3bit MLC Toshiba MG Series Enterprise 20TB 7200rpm 512MB MG10ACA20TE 3.5 SATA III Windows 11 Pro 25H2