Arduino Uno Serial Problems (57600 baud is broken)

Does it work better if you use Serial.begin(57599) or other numbers around 57600?

Good idea! Serial.begin(57850) seems to improve things...

For baud=057770, nonu2x_baud = 058823, u2x_baud = 057142 Use U2x, divisor = 34
For baud=057780, nonu2x_baud = 058823, u2x_baud = 057142 Use U2x, divisor = 34
For baud=057790, nonu2x_baud = 058823, u2x_baud = 057142 Use U2x, divisor = 34
For baud=057800, nonu2x_baud = 058823, u2x_baud = 057142 Use U2x, divisor = 34
For baud=057810, nonu2x_baud = 058823, u2x_baud = 057142 Use U2x, divisor = 34
For baud=057820, nonu2x_baud = 058823, u2x_baud = 057142 Use U2x, divisor = 34
For baud=057830, nonu2x_baud = 058823, u2x_baud = 057142 normal, divisor = 16
For baud=057840, nonu2x_baud = 058823, u2x_baud = 057142 normal, divisor = 16
For baud=057850, nonu2x_baud = 058823, u2x_baud = 057142 normal, divisor = 16
For baud=057860, nonu2x_baud = 058823, u2x_baud = 057142 normal, divisor = 16
For baud=057870, nonu2x_baud = 058823, u2x_baud = 057142 normal, divisor = 16