title: Estimating CI using confint() for GLMM leads to error in zetafun (np,ns)
body: <p>I have a GLMM with binary variables using R version 3.6.2 and lmerTEST 3.1-2 and I would like to get confidence intervals. So I've used <code>confint()</code> function.</p>
  
  <p>Here:</p>
  
  <pre><code>model71&lt;-glmer(fetale_Schwangerschaftskomplikationen~Infektion_in_Schwangerschaft+(1|Pat_ID),data=CED,family="binomial")
  </code></pre>
  
  <p>With the <code>summary()</code> function I get resulst without a warning, but for the confidence intervals I get:</p>
  
  <pre><code>confint(model71)
  Computing profile confidence intervals ...
  Error in zetafun(np, ns) : profiling detected new, lower deviance
  </code></pre>
  
  <p>I tried to solve the problem like described <a href="https://stackoverflow.com">here</a>, by boosting the <code>devtol</code> parameter using the <code>confint.merMod</code>.
  But this boosting isn't working for me. Boosting <code>devtol</code> to 1e-8,1e-7 or 1e-6 does give me the same output:</p>
  
  <pre><code>confint(model71)
  Computing profile confidence intervals ...
  Error in zetafun(np, ns) : profiling detected new, lower deviance
  </code></pre>
  
  <p>Does anyone have another idea for me, how i can solve this problem?
  (I am sorry for my bad English)
  Thanks</p>