Artefacts using U8G2_SSD1309_128X64_NONAME0_F_4W_SW_SPI OLED Display

[pcace]

Hi there, i am using an esp32 with a 64 x 128 px OLED Display with this: U8G2_SSD1309_128X64_NONAME0_F_4W_SW_SPI
the issue i am having is that pretty randomly the display starts to show artefacts:

https://youtu.be/fthJH_avVMU

it seems to be quite random if it starts or not, but once it did start, it will develop to something like this:

https://youtu.be/KcjPP9vwdH4

i have pretty much no clue where that comes from. at this esp there are several things connected:
SD Card (using spi2), GPS (TX/RX) and some buttons:
https://github.com/pcace/open-rally-computer/tree/dev

I just cannot find anything related to the issue here. can this be some kind of memory overflow or something?

any help would be great!

thanks a lot!