Solved
CubeMX setting GPDMA1 in UART repeats init members
Lines 19 and 26 are repeated. Mode is set to normal (0x0000) twice. The structure is already initialized to `={0};` it doesn't need to be overwritten once, let alone twice.
Initialized for STM32H563.
usart.c
/* GPDMA1_REQUEST_USART1_TX Init */
DMA_InitStruct.SrcAddress = 0x00000000U;
DMA_InitStruct.DestAddress = 0x00000000U;
DMA_InitStruct.Direction = LL_DMA_DIRECTION_MEMORY_TO_PERIPH;
DMA_InitStruct.BlkHWRequest = LL_DMA_HWREQUEST_SINGLEBURST;
DMA_InitStruct.DataAlignment = LL_DMA_DATA_ALIGN_ZEROPADD;
DMA_InitStruct.SrcBurstLength = 1;
DMA_InitStruct.DestBurstLength = 1;
DMA_InitStruct.SrcDataWidth = LL_DMA_SRC_DATAWIDTH_BYTE;
DMA_InitStruct.DestDataWidth = LL_DMA_DEST_DATAWIDTH_BYTE;
DMA_InitStruct.SrcIncMode = LL_DMA_SRC_INCREMENT;
DMA_InitStruct.DestIncMode = LL_DMA_DEST_FIXED;
DMA_InitStruct.Priority = LL_DMA_LOW_PRIORITY_MID_WEIGHT;
DMA_InitStruct.BlkDataLength = 0x00000000U;
DMA_InitStruct.Mode = LL_DMA_NORMAL;
DMA_InitStruct.TriggerMode = LL_DMA_TRIGM_BLK_TRANSFER;
DMA_InitStruct.TriggerPolarity = LL_DMA_TRIG_POLARITY_MASKED;
DMA_InitStruct.TriggerSelection = 0x00000000U;
DMA_InitStruct.Request = LL_GPDMA1_REQUEST_USART1_TX;
DMA_InitStruct.TransferEventMode = LL_DMA_TCEM_BLK_TRANSFER;
DMA_InitStruct.Mode = LL_DMA_NORMAL;
DMA_InitStruct.SrcAllocatedPort = LL_DMA_SRC_ALLOCATED_PORT1;
DMA_InitStruct.DestAllocatedPort = LL_DMA_DEST_ALLOCATED_PORT0;
DMA_InitStruct.LinkAllocatedPort = LL_DMA_LINK_ALLOCATED_PORT1;
DMA_InitStruct.LinkStepMode = LL_DMA_LSM_FULL_EXECUTION;
DMA_InitStruct.LinkedListBaseAddr = 0x00000000U;
DMA_InitStruct.LinkedListAddrOffset = 0x00000000U;
LL_DMA_Init(GPDMA1, LL_DMA_CHANNEL_1, &DMA_InitStruct);