BUG: interactive plot axes shrink to zero when moving cursor across plot #14317

Description of the problem

Recently, using evoked.plot_joint() calls to check some data quality, I discovered that the interactive plots are mysteriously shrinking down to nothing if my cursor moves over the figure. I've replicated this behavior on Linux and MacOs ipython sessions in the terminal (it happens with and without an IDE).

I haven't seen this behavior before, so I suspect we've made some recent changes to interactive plot API's that are resulting in the axes shrinking. Any ideas?

Steps to reproduce

import mne
test_path = mne.datasets.testing.data_path(download=False)
evk_path = test_path / "MEG/sample/sample_audvis_trunc-ave.fif"
evk = mne.read_evokeds(evk_path)
evk[0].plot_joint()

# move the cursor into the figure

Link to data

No response

Expected results

Plot elements should remain the original size.

Actual results

Plot elements shrink way down.

Additional information

$ mne sys_info
Platform Linux-6.8.0-139-generic-x86_64-with-glibc2.39 (X11)
Python 3.14.6 | packaged by conda-forge | (main, Jul 24 2026, 16:09:24) [GCC 14.3.0]
Executable /home/erica/miniconda3/envs/bids_dev26/bin/python3.14
CPU AMD Ryzen 9 3900X 12-Core Processor (24 cores)
Memory 62.7 GiB

Core
├☑ mne 1.14.0.dev29+gc166d8c19 (development, latest release is 1.13.2)
├☑ numpy 2.4.6 (OpenBLAS 0.3.33 with 12 threads via pthreads)
├☑ scipy 1.18.0
└☑ matplotlib 3.11.1 (backend=qtagg)

Numerical (optional)
├☑ scikit-learn 1.9.0
├☑ threadpoolctl 3.6.0
├☑ numba 0.66.0
├☑ nibabel 5.4.2
├☑ nilearn 0.13.1
├☑ dipy 1.12.1
├☑ openmeeg 2.5.16
├☑ pandas 3.0.3
├☑ h5io 0.2.5
├☑ h5py 3.16.0
└☐ unavailable python-picard, jamica, cupy

Visualization (optional)
├☑ pyvista 0.48.4 (OpenGL 4.6 (Core Profile) Mesa 25.2.8-0ubuntu0.24.04.2 via AMD Radeon RX 570 Series (radeonsi, polaris10, ACO, DRM 3.57, 6.8.0-139-generic))
├☑ pyvistaqt 0.12.0
├☑ vtk 9.6.2
├☑ qtpy 2.4.3 (PySide6=6.11.1)
├☑ pyqtgraph 0.14.0
├☑ mne-qt-browser 0.7.5
├☑ ipywidgets 8.1.8
├☑ trame 3.13.2
├☑ trame_client 3.13.2
├☑ trame_server 3.12.5
├☑ trame_vtk 2.11.14
├☑ trame_vuetify 3.2.5
└☐ unavailable ipympl, trame_pyvista

Ecosystem (optional)
├☑ mne-bids 0.20.0.dev24+g6564a0739
├☑ mne-nirs 0.7.3
├☑ mne-connectivity 0.8.1
├☑ mne-icalabel 0.9.0
├☑ mne-bids-pipeline 1.11.0.dev63+g9fe5082cc
├☑ autoreject 0.4.4
├☑ neo 0.14.5
├☑ eeglabio 0.1.3
├☑ edfio 0.4.14
├☑ curryreader 0.1.2
├☑ mffpy 0.11.0
├☑ pybv 0.8.1
├☑ pymef 1.4.8
├☑ antio 0.7.1
├☑ defusedxml 0.7.1
└☐ unavailable mne-features