Error sending partial to pool

Athis errors started yesterday after updating to 1.2.10, update today to 1.2.11 changed nothing, change of pool did not help also so it must be on my end.
2021-11-05T13:03:30.365 farmer chia.farmer.farmer : ERROR Error in GET /farmer https://xch-de.flexpool.io, 403
2021-11-05T13:03:36.617 farmer chia.farmer.farmer : ERROR Error sending partial to https://xch-de.flexpool.io, 403

my accepted partials droped from 100% to about 45% … I mine in windows GUI.