Oh, I found the solution…
Reading the Rotatory Encoder II source code I saw that for the buttons the npm Package “onoff” is used which reads GPIO Labels. RPi5 changed the names of the GPIO Pins. So just translate the desired “old” GPIO pin (for e.x. GPIO 27) into Board PIN (GPIO 27 = PIN 13) and then get the right GPIO label from the table below (GPIO 27 (non RPi5) = PIN 13 = gpio-426 (RPi 5) so in this case only enter “426” as GPIO Value).
sudo cat /sys/kernel/debug/gpio
[sudo] password for volumio:
gpiochip4: GPIOs 399-452, parent: platform/1f000d0000.gpio, pinctrl-rp1:
gpio-399 (ID_SD )
gpio-400 (ID_SC )
gpio-401 (PIN3 )
gpio-402 (PIN5 )
gpio-403 (PIN7 )
gpio-404 (PIN29 )
gpio-405 (PIN31 )
gpio-406 (PIN26 )
gpio-407 (PIN24 )
gpio-408 (PIN21 )
gpio-409 (PIN19 )
gpio-410 (PIN23 )
gpio-411 (PIN32 )
gpio-412 (PIN33 )
gpio-413 (PIN8 )
gpio-414 (PIN10 )
gpio-415 (PIN36 )
gpio-416 (PIN11 |rotary@12 ) in hi
gpio-417 (PIN12 |rotary@12 ) in hi
gpio-418 (PIN35 )
gpio-419 (PIN38 )
gpio-420 (PIN40 )
gpio-421 (PIN15 )
gpio-422 (PIN16 )
gpio-423 (PIN18 )
gpio-424 (PIN22 )
gpio-425 (PIN37 )
gpio-426 (PIN13 )
gpio-427 (PCIE_RP1_WAKE )
gpio-428 (FAN_TACH )
gpio-429 (HOST_SDA )
gpio-430 (HOST_SCL )
gpio-431 (ETH_RST_N |phy-reset ) out hi ACTIVE LOW
gpio-432 (- )
gpio-433 (CD0_IO0_MICCLK |cam0_reg ) out lo
gpio-434 (CD0_IO0_MICDAT0 )
gpio-435 (RP1_PCIE_CLKREQ_N )
gpio-436 (- )
gpio-437 (CD0_SDA )
gpio-438 (CD0_SCL )
gpio-439 (CD1_SDA )
gpio-440 (CD1_SCL )
gpio-441 (USB_VBUS_EN )
gpio-442 (USB_OC_N )
gpio-443 (RP1_STAT_LED |PWR ) out hi ACTIVE LOW
gpio-444 (FAN_PWM )
gpio-445 (CD1_IO0_MICCLK |cam1_reg ) out lo
gpio-446 (2712_WAKE )
gpio-447 (CD1_IO1_MICDAT1 )
gpio-448 (EN_MAX_USB_CUR )
gpio-449 (- )
gpio-450 (- )
gpio-451 (- )
gpio-452 (- )
gpiochip3: GPIOs 453-458, parent: platform/107d517c00.gpio, gpio-brcmstb@107d517c20:
gpio-453 (HDMI0_SCL )
gpio-454 (HDMI0_SDA )
gpio-455 (HDMI1_SCL )
gpio-456 (HDMI1_SDA )
gpio-457 (PMIC_SCL )
gpio-458 (PMIC_SDA )
gpiochip2: GPIOs 459-475, parent: platform/107d517c00.gpio, gpio-brcmstb@107d517c00:
gpio-459 (RP1_SDA )
gpio-460 (RP1_SCL )
gpio-461 (RP1_RUN |RP1 RUN pin ) out hi
gpio-462 (SD_IOVDD_SEL |vdd-sd-io ) out lo
gpio-463 (SD_PWR_ON |sd_vcc_reg ) out lo
gpio-464 (SD_CDET_N )
gpio-465 (SD_FLG_N )
gpio-466 (- )
gpio-467 (2712_WAKE )
gpio-468 (2712_STAT_LED |ACT ) out hi ACTIVE LOW
gpio-469 (- )
gpio-470 (- )
gpio-471 (PMIC_INT )
gpio-472 (UART_TX_FS )
gpio-473 (UART_RX_FS )
gpio-474 (- )
gpio-475 (- )
gpiochip1: GPIOs 476-479, parent: platform/107d508500.gpio, gpio-brcmstb@107d508520:
gpio-476 (WIFI_SDIO_D0 )
gpio-477 (WIFI_SDIO_D1 )
gpio-478 (WIFI_SDIO_D2 )
gpio-479 (WIFI_SDIO_D3 )
gpiochip0: GPIOs 480-511, parent: platform/107d508500.gpio, gpio-brcmstb@107d508500:
gpio-480 (- )
gpio-481 (2712_BOOT_CS_N |spi10 CS0 ) out hi ACTIVE LOW
gpio-482 (2712_BOOT_MISO )
gpio-483 (2712_BOOT_MOSI )
gpio-484 (2712_BOOT_SCLK )
gpio-485 (- )
gpio-486 (- )
gpio-487 (- )
gpio-488 (- )
gpio-489 (- )
gpio-490 (- )
gpio-491 (- )
gpio-492 (- )
gpio-493 (- )
gpio-494 (PCIE_SDA )
gpio-495 (PCIE_SCL )
gpio-496 (- )
gpio-497 (- )
gpio-498 (- )
gpio-499 (- )
gpio-500 (PWR_GPIO |pwr_button ) in hi ACTIVE LOW
gpio-501 (2712_G21_FS )
gpio-502 (- )
gpio-503 (- )
gpio-504 (BT_RTS )
gpio-505 (BT_CTS )
gpio-506 (BT_TXD )
gpio-507 (BT_RXD )
gpio-508 (WL_ON |wl_on_reg ) out hi
gpio-509 (BT_ON |shutdown ) out hi
gpio-510 (WIFI_SDIO_CLK )
gpio-511 (WIFI_SDIO_CMD )