Tensorboard is always showing old data

I have a code that's supposed to show a simple line on Tensorboard.

import torch.utils.tensorboard as tb
import tempfile
log_dir = tempfile.mkdtemp()
print(log_dir)
%tensorboard --logdir {log_dir}

logger = tb.SummaryWriter(log_dir+'/test3', flush_secs=1)
logger.add_scalar('first/some_number', 0, global_step=1)
logger.add_scalar('first/some_number', 1, global_step=2)

But forsome reason, my tensorboard is not updating. It only shows the data that I did previously. Currently the only way I update/refresh my tensorboard is by restarting my PC. Any other solutions? Thank you!