OpenCV Stitcher fails and return error code 1 and None

Question

I am trying to create a mosaic of thermal images using OpenCV Stitcher. I am using python 3.7 and OpenCV 3.4.2. when I am trying to stitch a panorama with at least 40% overlap it fails. I get error code 1 which means I don't have enough key-points. how can I overcome this?

left image , right image

here is the code:

 images_path = glob.glob(folder_images+"\*.tif")
 images=[]
 for i in range(0,len(images_path)):
        
     img = cv2.imread(images_path[i],cv2.IMREAD_UNCHANGED)
     img=normal_image(image=img)# normalize by min max from float to gray
     images.append(img)
 stitcher =cv2.createStitcher()
 result  = stitcher.stitch(images)
 cv2.imwrite("out.tif",result[1])

and as I said the result=(1, None)

the second weird thing that I encountered is that when I'm trying to stitch a result of a previous stitch I get the result (1, None) again. when I take a batch of 10 images I get good result, when splitting the images to two groups and stitch each group I get good result, when trying to stitch the two outputs I get the error again. I hope someone can help me with these two issues.

thank you!