stack expects each tensor to be equal size but got [7, 768] at entry 0 and [8, 768] at entry 1
    ca_embedding = torch.stack(tns_embedding) 
    embeddings.append(ca_embedding)

the shape for the first is ca_embedding shape is  torch.Size([7, 768])
the shape for the second is ca_embedding shape is  torch.Size([8, 768])