Might be that the chip’s flash is protected. At least that’s what I read when going through [SOLVED] STM32L052 failed to erase sectors - J-Link/Flasher related - SEGGER - Forum and Unlocking and Erasing FLASH with Segger J-Link | MCU on Eclipse. You might want to try to erase / unlock the tool with JLink on the command line or some other tool (e.g., openocd can do that, and probably also STM32CubeProgrammer from STMicroelectronics themselves).
The update to platform-ststm32 v10.0.0 also updated JLink to v6.88b because a user asked for it since there was a bug in the old version and confirmed the new working (Updating JLink version).You might want to try adding
platform_packages =
tool-jlink@1.65200.0
to the platformio.ini to revert back to JLink 6.52. That is, if the new JLink version hasn’t already locked your chip, then you absolutely need to unlock it.