Elasticsearch (sort of) losing pipelines on restart

Elastic Stack Elasticsearch
4

thanks for you reply.
yes, all are master eligible

curl -XGET 'localhost:9200/_cat/nodes?v&pretty'
ip          heap.percent ram.percent cpu load_1m load_5m load_15m node.role master name
172.31.1.22           64          81   0    0.01    0.02     0.05 md        -      node02
172.31.1.21           24          80   1    0.00    0.01     0.05 md        *      node01
172.31.1.20           13          99   0    0.00    0.01     0.05 mi        -      node00

minimum_master_nodes ist set to 2 on all three nodes

discovery.zen.minimum_master_nodes: 2