<p dir="auto">The following code does not show markers.</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="my_data = [1,2,5,3,0]
sns.lineplot(data = my_data,markers=True);"><pre class="notranslate"><code class="notranslate">my_data = [1,2,5,3,0]
sns.lineplot(data = my_data,markers=True);
</code></pre></div>
<p dir="auto">this code doesn't show markers either</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="ax = sns.lineplot(x = [1,2,3,4,5], y=[1,2,5,3,0],markers=True);"><pre class="notranslate"><code class="notranslate">ax = sns.lineplot(x = [1,2,3,4,5], y=[1,2,5,3,0],markers=True);
</code></pre></div>
<p dir="auto">on the other hand, this code does:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="my_data=pd.DataFrame([1,2,5,3,0])
sns.lineplot(data = my_data,markers=True);"><pre class="notranslate"><code class="notranslate">my_data=pd.DataFrame([1,2,5,3,0])
sns.lineplot(data = my_data,markers=True);
</code></pre></div>
<p dir="auto">seaborn version 0.11.1<br>
matplotlib version 3.3.1</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/35338267/115969765-ae749a80-a50c-11eb-995b-8e9e9b7a0b9f.png"><img src="https://user-images.githubusercontent.com/35338267/115969765-ae749a80-a50c-11eb-995b-8e9e9b7a0b9f.png" alt="image" style="max-width: 100%;"></a></p>
<p dir="auto">I am running matplotlib 3.0.2 and Seaborn 0.9.0 in python 3.7 on MacOs.<br>
There appears to be a bug in Seaborn which makes its line plot function ignore the markers argument. The matplotlib plot still plots the markers, i.e. this is not the problem and I also set lines.markeredgewidth as was recommended in an earlier issue on missing markers. Still whatever I set markers to, line plot accepts this and ignores it.</p>
<p dir="auto">See a broken example: Matplotlib plots as it should, but Seaborn shows no markers:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt

sns.set()
sns.set_context(&quot;paper&quot;,rc={&quot;lines.linewidth&quot;: 2.5,'lines.markeredgewidth': 1,'lines.markersize': 10})

df_test = pd.DataFrame(data={'x':[1,2,3],'y':[4,5,6]})
plt.figure()
plt.plot(df_test['x'],df_test['y'],'o-')
plt.figure()
sns.lineplot(data=df_test,x='x',y='y',markers=['o'])
plt.show()"><pre class="notranslate"><code class="notranslate">import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt

sns.set()
sns.set_context("paper",rc={"lines.linewidth": 2.5,'lines.markeredgewidth': 1,'lines.markersize': 10})

df_test = pd.DataFrame(data={'x':[1,2,3],'y':[4,5,6]})
plt.figure()
plt.plot(df_test['x'],df_test['y'],'o-')
plt.figure()
sns.lineplot(data=df_test,x='x',y='y',markers=['o'])
plt.show()
</code></pre></div>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/13691026/53176872-f4e0ae80-35bc-11e9-9224-18417d406f50.png"><img src="https://user-images.githubusercontent.com/13691026/53176872-f4e0ae80-35bc-11e9-9224-18417d406f50.png" alt="image" style="max-width: 100%;"></a></p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/13691026/53176853-e7c3bf80-35bc-11e9-99e5-911b59380b27.png"><img src="https://user-images.githubusercontent.com/13691026/53176853-e7c3bf80-35bc-11e9-99e5-911b59380b27.png" alt="image" style="max-width: 100%;"></a></p>