Esp8266-12F can't drive OLED when using SSD1306_128X64_NONAME_SW_I2C

[mogerr]

Can't drive SD1306 OLED when using routines likes "Hello World"

U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(/* clock=*/ 9, /* data=*/ 10, /* reset=*/ U8X8_PIN_NONE); // Digispark ATTiny85

The same code can be driven when esp8266-12E development board with cp2102 is used, but cannot be driven when esp8266-12F development board with cp2102 or CH340 is used. It's strange and maddening.

scl=9, sda=10 comes as a software driver pin for OLED.

Has anyone encountered the same problem?