spyder-terminal Spyder built in terminal has a large typing delay

Issue Report Checklist

[x] Searched the issues page for similar reports
[x] Read the relevant sections of the Spyder Troubleshooting Guide and followed its advice
[ ] Reproduced the issue after updating with conda update spyder (or pip, if not using Anaconda)
[ ] Could not reproduce inside jupyter qtconsole (if console-related)
[x] Tried basic troubleshooting (if a bug/error)
- [x] Restarted Spyder
- [x] Reset preferences with spyder --reset
- [ ] Reinstalled the latest version of Anaconda
- [ ] Tried the other applicable steps from the Troubleshooting Guide
[x] Completed the Problem Description, Steps to Reproduce and Version sections below

Problem Description

First of all, thanks for including the spyder-terminal in the standalone installers now as well! However, currently the typing delay is rather large, making the spyder-terminal not very usable.

Using the built in terminal typing any command has a 1-2 second of delay.

What steps reproduce the problem?

Open Spyder
Go to the Terminal tab
Type ls and press Enter as fast as you can.

What is the expected output? What do you see instead?

Expected output The command is typed on the command line without noticeable delay and the output is shown directly as I press Enter. If I for example visit the underlying web terminal at 127.0.0.1:8073 that is how it works.

Actual output All my input is delayed for 1-2 seconds. It's as if I am typing over a very slow network connection.

Paste Traceback/Error Below (if applicable)

>>> Uncaught TypeError: Cannot read property 'fit' of undefined
 _distutils_hack/__init__.pyc:17: UserWarning: Distutils was imported before Setuptools, but importing Setuptools also replaces the `distutils` module in `sys.modules`. This may lead to undesirable behaviors or errors. To avoid these issues, avoid using distutils directly, ensure that setuptools is installed in the traditional way (e.g. not an editable install), and/or make sure that setuptools is always imported before distutils.
_distutils_hack/__init__.pyc:30: UserWarning: Setuptools is replacing distutils.

Versions

Spyder version: 5.3.0 None
Python version: 3.9.5 64-bit
Qt version: 5.15.2
PyQt5 version: 5.15.6
Operating System: Darwin 21.4.0

Dependencies

# Mandatory:
applaunchservices >=0.1.7            :  0.2.1 (OK)
atomicwrites >=1.2.0                 :  1.4.0 (OK)
chardet >=2.0.0                      :  4.0.0 (OK)
cloudpickle >=0.5.0                  :  2.0.0 (OK)
cookiecutter >=1.6.0                 :  1.7.3 (OK)
diff_match_patch >=20181111          :  20200713 (OK)
intervaltree >=3.0.2                 :  3.1.0 (OK)
IPython >=7.31.1;<8.0.0              :  7.32.0 (OK)
jedi >=0.17.2;<0.19.0                :  0.18.1 (OK)
jellyfish >=0.7                      :  0.9.0 (OK)
jsonschema >=3.2.0                   :  4.4.0 (OK)
keyring >=17.0.0                     :  23.5.0 (OK)
nbconvert >=4.0                      :  6.4.5 (OK)
numpydoc >=0.6.0                     :  1.2.1 (OK)
parso >=0.7.0;<0.9.0                 :  0.8.3 (OK)
pexpect >=4.4.0                      :  4.8.0 (OK)
pickleshare >=0.4                    :  0.7.5 (OK)
psutil >=5.3                         :  5.9.0 (OK)
pygments >=2.0                       :  2.11.2 (OK)
pylint >=2.5.0                       :  2.13.3 (OK)
pyls_spyder >=0.4.0                  :  0.4.0 (OK)
pylsp >=1.4.1;<1.5.0                 :  1.4.1 (OK)
pylsp_black >=1.2.0                  :  1.2.0 (OK)
qdarkstyle >=3.0.2;<3.1.0            :  3.0.3 (OK)
qstylizer >=0.1.10                   :  0.2.1 (OK)
qtawesome >=1.0.2                    :  1.1.1 (OK)
qtconsole >=5.3.0;<5.4.0             :  5.3.0 (OK)
qtpy >=2.0.1                         :  2.0.1 (OK)
rtree >=0.9.7                        :  0.9.7 (OK)
setuptools >=49.6.0                  :  60.10.0 (OK)
sphinx >=0.6.6                       :  4.5.0 (OK)
spyder_kernels >=2.3.0;<2.4.0        :  2.3.0 (OK)
textdistance >=4.2.0                 :  4.2.2 (OK)
three_merge >=0.1.1                  :  0.1.1 (OK)
watchdog >=0.10.3                    :  2.1.7 (OK)
zmq >=17                             :  22.3.0 (OK)

# Optional:
cython >=0.21                        :  0.29.28 (OK)
matplotlib >=3.0.0                   :  3.5.1 (OK)
numpy >=1.7                          :  1.22.3 (OK)
pandas >=1.1.1                       :  1.4.1 (OK)
scipy >=0.17.0                       :  1.8.0 (OK)
sympy >=0.7.3                        :  1.10.1 (OK)

# Spyder plugins:
spyder_terminal.terminalplugin 1.2.2 :  1.2.2 (OK)