Please use 3 channels images.
More ,could you change as below if trigger new training?
zoom_min: 0.1 **(set to 1.0)**
zoom_max: 0.1 **(set to 1.0)**
}
}
And, if trigger new evaluation only, please try below.
postprocessing_config {
target_class_config {
key: "standard"
value {
clustering_config {
clustering_algorithm: DBSCAN
dbscan_confidence_threshold: 0.9 **(try lower value)**
coverage_threshold: 0.00499999988824
dbscan_eps: 0.20000000298
dbscan_min_samples: 0.0500000007451
minimum_bounding_box_height: 20 **(set to lower value)**