The main issue is likely not the umbrella type, but the apparent size of the light. A modifier only looks soft when it is large relative to the subject, which usually means placing it fairly close. If the umbrella is too far away, it behaves more like a small, hard light source and will emphasize shiny skin and forehead hotspots.

For red-carpet/event work, large modifiers often can’t be placed close enough, so umbrellas may not soften the light much. In that situation, one practical approach is to reduce how much the flash contributes and rely more on ambient exposure by raising ISO as needed. You may even get better results by simplifying the setup rather than expecting distant umbrellas to create very soft light.

In short: move the modifier closer if possible; if that isn’t practical, lower the flash’s dominance and use more ambient light.