Server times out because of Command Blocks

I got 6 command blocks on repeat. 3 summon particles around the 3 armor stands and 3 rotate the 3 armor stands. To know what exactly I mean, watch this Video from 7:30 https://youtu.be/1DjAt-WuJFA?si=YAlaFrzu4ebj_m0E&t=449 
This causes the server to completly lag out and kick everyone after a while with the message "Timed out". The TPS graph is completly fine but it still lags (Chat delayed, cant open chests etc). I checked the Server stats and the CPU was fine (20%), RAM was completly fine (6GB/16GB) and tps was constantly on 20. So whats the problem?