Several miners in solo-mining

Hi, I have a problem, I installed 6 workers with prune mode and snapshot but the synchronization is no longer progressing, in the logs I regularly have the following message:

INFO pherry] bridge() exited with error: Failed to connect to substrate
Caused by:
0: Rpc error: Networking or low-level protocol error: Connection rejected with status code: 429
1: Networking or low-level protocol error: Connection rejected with status code: 429
2: Connection rejected with status code: 429
Too many connections. Try again in a while.

How to do ?

Isn’t it possible to have several workers in solo-mining mode with the same Internet connection (I have a 1Gb fiber connection)?

I don’t want to switch to PRB mode.

When I leave only one worker running, everything seems to start fine again.

Thanks in advance